{"id":69,"date":"2022-08-16T19:49:27","date_gmt":"2022-08-16T23:49:27","guid":{"rendered":"https:\/\/opentextbc.ca\/alfm2\/?post_type=chapter&p=69"},"modified":"2025-09-18T16:47:52","modified_gmt":"2025-09-18T20:47:52","slug":"estimating-answers-in-subtraction","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/alfm2\/chapter\/estimating-answers-in-subtraction\/","title":{"raw":"Topic E: Estimating Answers in Subtraction","rendered":"Topic E: Estimating Answers in Subtraction"},"content":{"raw":"You have learned how to round numbers. Now you can use that skill in rounding numbers to find an approximate difference.\r\n\r\nBy estimating your answer first, you can tell if your answer is sensible.\r\n\r\nIn these examples, estimate the answer. Round each number BEFORE you subtract.\r\n\r\nExample A: [latex]\\begin{array}[t]{rrrrr} &47&\\text{rounds to}&&50 \\\\-&26&\\text{rounds to}&-&30 \\\\ \\hline &&&&20 \\end{array}[\/latex]\r\n\r\nExample B: [latex]\\begin{array}[t]{rrrrr} &870&\\text{rounds to}&&900 \\\\-&342&\\text{rounds to}&-&300 \\\\ \\hline &&&&600 \\end{array}[\/latex]\r\n\r\nExample C: [latex]\\begin{array}[t]{rrrrr} &24\\,397&\\text{rounds to}&&24\\,000 \\\\-&6\\,148&\\text{rounds to}&-&6\\,000 \\\\ \\hline &&&&18\\,000 \\end{array}[\/latex]\r\n\r\nUsually you estimate to the largest place value that you can.\r\n
\r\n

Exercise One<\/p>\r\n\r\n<\/header>\r\n

\r\n\r\nEstimate the differences. Round the numbers before you subtract. Check your work using the answer key at the end of the exercise.\r\n
    \r\n \t
  1. [latex]\\begin{array}[t]{rrrrr}&9\\,963&\\approx&&10\\,000 \\\\-&7\\,099&\\approx&-&7\\,000 \\\\ \\hline &&&&3\\,000 \\end{array}[\/latex]<\/li>\r\n \t
  2. [latex]\\begin{array}[t]{rrrrr}&70\\,534&\\approx&&71\\,000 \\\\-&7\\,689&\\approx&-&8\\,000 \\\\ \\hline &&&&63\\,000 \\end{array}[\/latex]<\/li>\r\n \t
  3. [latex]\\begin{array}[t]{rr}&687\\\\-&438\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  4. [latex]\\begin{array}[t]{rr}&754\\\\-&236\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  5. [latex]\\begin{array}[t]{rr}&8\\,442\\\\-& 1\\, 876\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  6. [latex]\\begin{array}[t]{rr}&5 \\,630\\\\-& 1 \\,752\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  7. [latex]\\begin{array}[t]{rr}&5 \\,342\\\\-& 3 \\,647\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  8. [latex]\\begin{array}[t]{rr}&7 \\,111\\\\-& 5 \\,982\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  9. [latex]\\begin{array}[t]{rr}&6 \\,031 \\\\-& 2\\, 899\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  10. [latex]\\begin{array}[t]{rr}&41 \\,573\\\\-& 4\\, 846\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  11. [latex]\\begin{array}[t]{rr}&36 \\,154\\\\-& 9 \\,038\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  12. [latex]\\begin{array}[t]{rr}&46 \\,124 \\\\-& 9 \\,762\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  13. [latex]\\begin{array}[t]{rr}&54 \\,751 \\\\-& 7 \\,896\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  14. [latex]\\begin{array}[t]{rr}&72 \\,450 \\\\-& 31\\, 924\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  15. [latex]\\begin{array}[t]{rr}&81 \\,692 \\\\-& 53\\, 908\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  16. [latex]\\begin{array}[t]{rr}&92 \\,163 \\\\-& 45\\, 517\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  17. [latex]\\begin{array}[t]{rr}&171 \\,234\\\\-& 82\\, 169\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
  18. [latex]\\begin{array}[t]{rr}&102 \\,085 \\\\-& 36 \\,526\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n<\/ol>\r\nAnswers to Exercise One<\/strong>\r\n
      \r\n \t
    1. 10000<\/span> \u2212 7000<\/span> = 3000<\/span><\/li>\r\n \t
    2. 71000<\/span> \u2212 8000<\/span> = 63000<\/span><\/li>\r\n \t
    3. 700 \u2212 400 = 300<\/li>\r\n \t
    4. 800 \u2212 200 = 600<\/li>\r\n \t
    5. 8000<\/span> \u2212 2000<\/span>\u00a0 = 6000<\/span><\/li>\r\n \t
    6. 6000<\/span> \u2212 2000<\/span>\u00a0 = 4000<\/span><\/li>\r\n \t
    7. 5000<\/span> \u2212 4000<\/span>\u00a0 = 1000<\/span><\/li>\r\n \t
    8. 7000<\/span> \u2212\u00a0 6000<\/span>\u00a0 =\u00a0 1000<\/span><\/li>\r\n \t
    9. 6000<\/span> \u2212 3000<\/span> = 3000<\/span><\/li>\r\n \t
    10. 42000<\/span> \u2212 5000<\/span> = 37000<\/span><\/li>\r\n \t
    11. 36000<\/span> \u2212 9000<\/span> = 27000<\/span><\/li>\r\n \t
    12. 46000<\/span> \u2212 10000<\/span>\u00a0 = 36000<\/span><\/li>\r\n \t
    13. 55000<\/span> \u2212 8000<\/span>\u00a0 =\u00a0 47000<\/span><\/li>\r\n \t
    14. 70000<\/span> \u2212 30000<\/span>\u00a0 =\u00a0 40000<\/span><\/li>\r\n \t
    15. 80000<\/span> \u2212 50000<\/span>\u00a0 = 30000<\/span><\/li>\r\n \t
    16. 90000<\/span> \u2212 50000<\/span>\u00a0 =\u00a0 40000<\/span><\/li>\r\n \t
    17. 170000<\/span> \u2212 80000<\/span> = 90000<\/span><\/li>\r\n \t
    18. 100000<\/span> \u2212 40000<\/span> = 60000<\/span><\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n

      Estimating Answers in Subtraction Word Problems<\/h1>\r\nWhen you are solving word problems, an estimate tells you if your answer makes sense. You can use your estimate to help you check your answers. If your answer and the estimate are not close, then you know that you should subtract your numbers again.\r\n
      \r\n

      Exercise Two<\/p>\r\n\r\n<\/header>\r\n

      \r\n\r\nEstimate the following answers. Be sure to round to the largest place value possible before adding or subtracting. Remember to circle <\/span> the information and underline<\/span> what is being asked. Check your work using the answer key at the end of the exercise.\r\n\r\nExample:\r\n\r\nOn a recent petition about sales tax, Mulan had 2865<\/span> people sign. Arnav had 1564<\/span> people sign the petition. Estimate how many more people Mulan had sign than Arnav.\r\n\r\nOn a recent petition about sales tax, Mulan had 2865<\/span><\/span> people sign. Arnav had 1564<\/span><\/span> people sign the petition. Estimate how many more people Mulan had sign than Arnav.\r\n\r\n[latex]\\begin{array}[t]{rrrrr}&2\\,865&\\text{Estimate: }&&3\\,000\\\\ \u2212 &1\\,564&&-&2\\,000\\\\ \\hline &&&&1\\,000\\end{array}[\/latex]\r\n\r\nMulan had 1 000 more people sign the petition.\r\n
        \r\n \t
      1. On Tuesday, a coffee shop had sales of $8523<\/span>. On Wednesday, the same coffee shop had sales of $6914<\/span>. Estimate the difference between Tuesday\u2019s sales and Wednesday\u2019s sales.<\/li>\r\n \t
      2. Last week, 4931<\/span> passengers used the ABE Taxi Company. This week, there were 3491<\/span> passengers. Estimate how many more passengers used ABE Taxi Company last week.<\/li>\r\n \t
      3. In Japan, people chew 52700<\/span> tons of gum. In Russia, people chew 25700<\/span> tons of gum. Estimate the how many more tons of gum the Japanese chew.<\/li>\r\n \t
      4. In Colombia there are 1897<\/span> bird species. In China, there are 1319<\/span> bird species. Estimate how many more bird species there are in Colombia.<\/li>\r\n \t
      5. The whale shark weighs 30500<\/span> kilograms. The basking shark weighs 9258<\/span> kilograms. Estimate how much more the whale shark weighs.<\/li>\r\n \t
      6. In India there were 155204<\/span> post offices in 2007. In China there were 59886<\/span> post offices. Estimate the difference.<\/li>\r\n \t
      7. By 2008, the Montreal Canadiens had played the most games 5792<\/span>. The Buffalo Sabres had played 2952<\/span>. Estimate how many more games the Montreal Canadiens had played.<\/li>\r\n \t
      8. In 2006, the population of Kelowna was 162276<\/span>. The population of Prince George was 83225<\/span>. Estimate how many more people live in Kelowna in 2006.<\/li>\r\n<\/ol>\r\nAnswers to Exercise Two<\/strong>\r\n
          \r\n \t
        1. $9000<\/span> \u2212 $7000 = $2000<\/span><\/span><\/li>\r\n \t
        2. 5000<\/span> \u2212 3000<\/span> = 2000<\/span> passengers<\/li>\r\n \t
        3. 50000<\/span> \u2212 30000<\/span> = 20000<\/span> tons<\/li>\r\n \t
        4. 2000<\/span> \u2212 1000<\/span> = 1000<\/span> species<\/li>\r\n \t
        5. 31000<\/span> \u2212 9000<\/span> = 22000<\/span> kilograms<\/li>\r\n \t
        6. 160000<\/span> \u2212 60000<\/span> = 100000<\/span> post offices<\/li>\r\n \t
        7. 6000<\/span> \u2212 3000<\/span> = 3000<\/span> games<\/li>\r\n \t
        8. 160000<\/span> \u2212 80000<\/span> = 80000<\/span> people<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n

          Topic E: Self-Test<\/h1>\r\nMark\u00a0 \u00a0 \/18\u00a0\u00a0\u00a0 Aim 14\/18<\/strong>\r\n
            \r\n \t
          1. Estimate the differences.\u00a0 Show your work. (12 marks)\r\n
              \r\n \t
            1. [latex]\\begin{array}[t]{rr}&73\\\\-&34\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            2. [latex]\\begin{array}[t]{rr}&67\\\\-&18\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            3. [latex]\\begin{array}[t]{rr}&896\\\\-&385\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            4. [latex]\\begin{array}[t]{rr}&467\\\\-&214\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            5. [latex]\\begin{array}[t]{rr}&4\\,071\\\\-& 2\\, 986\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            6. [latex]\\begin{array}[t]{rr}&5 \\,946 \\\\-& 4 \\,281\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            7. [latex]\\begin{array}[t]{rr}&57\\, 201\\\\-& 5 \\,892\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            8. [latex]\\begin{array}[t]{rr}&23 \\,006\\\\-& 4 \\,999\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            9. [latex]\\begin{array}[t]{rr}&49 \\,053\\\\-& 28 \\,954\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            10. [latex]\\begin{array}[t]{rr}&36 \\,174\\\\-& 16\\,925\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            11. [latex]\\begin{array}[t]{rr}&86 \\,502 \\\\-& 26 \\,590\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n \t
            12. [latex]\\begin{array}[t]{rr}&943 \\,982 \\\\-& 721\\, 354\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
            13. Estimate each of the following word problems. (6 marks) Be sure to include the unit of measure in your answer. (2 marks each) Be sure to circle <\/span> information and underline<\/span> what is being asked.\r\n
                \r\n \t
              1. A magazine has 54823<\/span> readers. Last year the magazine had 26876<\/span> readers. By how much did number of readers increase?<\/li>\r\n \t
              2. In 2009, the number of marriages per year in Japan was 964702<\/span>. The number of marriages per year in Egypt was 525412<\/span>. How many more marriages were there in Japan than Egypt?<\/li>\r\n \t
              3. In 2010, in France there were 235846<\/span> people with the last name Martin. There were 78177<\/span> people with the last name Moreau. How many more Martins were there?<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n

                Answers to Topic E Self-Test<\/h2>\r\n
                  \r\n \t
                1. \r\n
                    \r\n \t
                  1. 40<\/li>\r\n \t
                  2. 50<\/li>\r\n \t
                  3. 500<\/li>\r\n \t
                  4. 300<\/li>\r\n \t
                  5. 1000<\/span><\/li>\r\n \t
                  6. 2000<\/span><\/li>\r\n \t
                  7. 51000<\/span><\/li>\r\n \t
                  8. 18000<\/span><\/li>\r\n \t
                  9. 20000<\/span><\/li>\r\n \t
                  10. 20000<\/span><\/li>\r\n \t
                  11. 60000<\/span><\/li>\r\n \t
                  12. 200000<\/span><\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                  13. \r\n
                      \r\n \t
                    1. 20000<\/span> readers<\/li>\r\n \t
                    2. 500000<\/span> marriages<\/li>\r\n \t
                    3. 160000<\/span> Martins<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","rendered":"

                      You have learned how to round numbers. Now you can use that skill in rounding numbers to find an approximate difference.<\/p>\n

                      By estimating your answer first, you can tell if your answer is sensible.<\/p>\n

                      In these examples, estimate the answer. Round each number BEFORE you subtract.<\/p>\n

                      Example A: [latex]\\begin{array}[t]{rrrrr} &47&\\text{rounds to}&&50 \\\\-&26&\\text{rounds to}&-&30 \\\\ \\hline &&&&20 \\end{array}[\/latex]<\/p>\n

                      Example B: [latex]\\begin{array}[t]{rrrrr} &870&\\text{rounds to}&&900 \\\\-&342&\\text{rounds to}&-&300 \\\\ \\hline &&&&600 \\end{array}[\/latex]<\/p>\n

                      Example C: [latex]\\begin{array}[t]{rrrrr} &24\\,397&\\text{rounds to}&&24\\,000 \\\\-&6\\,148&\\text{rounds to}&-&6\\,000 \\\\ \\hline &&&&18\\,000 \\end{array}[\/latex]<\/p>\n

                      Usually you estimate to the largest place value that you can.<\/p>\n

                      \n
                      \n

                      Exercise One<\/p>\n<\/header>\n

                      \n

                      Estimate the differences. Round the numbers before you subtract. Check your work using the answer key at the end of the exercise.<\/p>\n

                        \n
                      1. [latex]\\begin{array}[t]{rrrrr}&9\\,963&\\approx&&10\\,000 \\\\-&7\\,099&\\approx&-&7\\,000 \\\\ \\hline &&&&3\\,000 \\end{array}[\/latex]<\/li>\n
                      2. [latex]\\begin{array}[t]{rrrrr}&70\\,534&\\approx&&71\\,000 \\\\-&7\\,689&\\approx&-&8\\,000 \\\\ \\hline &&&&63\\,000 \\end{array}[\/latex]<\/li>\n
                      3. [latex]\\begin{array}[t]{rr}&687\\\\-&438\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      4. [latex]\\begin{array}[t]{rr}&754\\\\-&236\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      5. [latex]\\begin{array}[t]{rr}&8\\,442\\\\-& 1\\, 876\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      6. [latex]\\begin{array}[t]{rr}&5 \\,630\\\\-& 1 \\,752\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      7. [latex]\\begin{array}[t]{rr}&5 \\,342\\\\-& 3 \\,647\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      8. [latex]\\begin{array}[t]{rr}&7 \\,111\\\\-& 5 \\,982\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      9. [latex]\\begin{array}[t]{rr}&6 \\,031 \\\\-& 2\\, 899\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      10. [latex]\\begin{array}[t]{rr}&41 \\,573\\\\-& 4\\, 846\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      11. [latex]\\begin{array}[t]{rr}&36 \\,154\\\\-& 9 \\,038\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      12. [latex]\\begin{array}[t]{rr}&46 \\,124 \\\\-& 9 \\,762\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      13. [latex]\\begin{array}[t]{rr}&54 \\,751 \\\\-& 7 \\,896\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      14. [latex]\\begin{array}[t]{rr}&72 \\,450 \\\\-& 31\\, 924\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      15. [latex]\\begin{array}[t]{rr}&81 \\,692 \\\\-& 53\\, 908\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      16. [latex]\\begin{array}[t]{rr}&92 \\,163 \\\\-& 45\\, 517\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      17. [latex]\\begin{array}[t]{rr}&171 \\,234\\\\-& 82\\, 169\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                      18. [latex]\\begin{array}[t]{rr}&102 \\,085 \\\\-& 36 \\,526\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n<\/ol>\n

                        Answers to Exercise One<\/strong><\/p>\n

                          \n
                        1. 10000<\/span> \u2212 7000<\/span> = 3000<\/span><\/li>\n
                        2. 71000<\/span> \u2212 8000<\/span> = 63000<\/span><\/li>\n
                        3. 700 \u2212 400 = 300<\/li>\n
                        4. 800 \u2212 200 = 600<\/li>\n
                        5. 8000<\/span> \u2212 2000<\/span>\u00a0 = 6000<\/span><\/li>\n
                        6. 6000<\/span> \u2212 2000<\/span>\u00a0 = 4000<\/span><\/li>\n
                        7. 5000<\/span> \u2212 4000<\/span>\u00a0 = 1000<\/span><\/li>\n
                        8. 7000<\/span> \u2212\u00a0 6000<\/span>\u00a0 =\u00a0 1000<\/span><\/li>\n
                        9. 6000<\/span> \u2212 3000<\/span> = 3000<\/span><\/li>\n
                        10. 42000<\/span> \u2212 5000<\/span> = 37000<\/span><\/li>\n
                        11. 36000<\/span> \u2212 9000<\/span> = 27000<\/span><\/li>\n
                        12. 46000<\/span> \u2212 10000<\/span>\u00a0 = 36000<\/span><\/li>\n
                        13. 55000<\/span> \u2212 8000<\/span>\u00a0 =\u00a0 47000<\/span><\/li>\n
                        14. 70000<\/span> \u2212 30000<\/span>\u00a0 =\u00a0 40000<\/span><\/li>\n
                        15. 80000<\/span> \u2212 50000<\/span>\u00a0 = 30000<\/span><\/li>\n
                        16. 90000<\/span> \u2212 50000<\/span>\u00a0 =\u00a0 40000<\/span><\/li>\n
                        17. 170000<\/span> \u2212 80000<\/span> = 90000<\/span><\/li>\n
                        18. 100000<\/span> \u2212 40000<\/span> = 60000<\/span><\/li>\n<\/ol>\n<\/div>\n<\/div>\n

                          Estimating Answers in Subtraction Word Problems<\/h1>\n

                          When you are solving word problems, an estimate tells you if your answer makes sense. You can use your estimate to help you check your answers. If your answer and the estimate are not close, then you know that you should subtract your numbers again.<\/p>\n

                          \n
                          \n

                          Exercise Two<\/p>\n<\/header>\n

                          \n

                          Estimate the following answers. Be sure to round to the largest place value possible before adding or subtracting. Remember to circle <\/span> the information and underline<\/span> what is being asked. Check your work using the answer key at the end of the exercise.<\/p>\n

                          Example:<\/p>\n

                          On a recent petition about sales tax, Mulan had 2865<\/span> people sign. Arnav had 1564<\/span> people sign the petition. Estimate how many more people Mulan had sign than Arnav.<\/p>\n

                          On a recent petition about sales tax, Mulan had 2865<\/span><\/span> people sign. Arnav had 1564<\/span><\/span> people sign the petition. Estimate how many more people Mulan had sign than Arnav.<\/p>\n

                          [latex]\\begin{array}[t]{rrrrr}&2\\,865&\\text{Estimate: }&&3\\,000\\\\ \u2212 &1\\,564&&-&2\\,000\\\\ \\hline &&&&1\\,000\\end{array}[\/latex]<\/p>\n

                          Mulan had 1 000 more people sign the petition.<\/p>\n

                            \n
                          1. On Tuesday, a coffee shop had sales of $8523<\/span>. On Wednesday, the same coffee shop had sales of $6914<\/span>. Estimate the difference between Tuesday\u2019s sales and Wednesday\u2019s sales.<\/li>\n
                          2. Last week, 4931<\/span> passengers used the ABE Taxi Company. This week, there were 3491<\/span> passengers. Estimate how many more passengers used ABE Taxi Company last week.<\/li>\n
                          3. In Japan, people chew 52700<\/span> tons of gum. In Russia, people chew 25700<\/span> tons of gum. Estimate the how many more tons of gum the Japanese chew.<\/li>\n
                          4. In Colombia there are 1897<\/span> bird species. In China, there are 1319<\/span> bird species. Estimate how many more bird species there are in Colombia.<\/li>\n
                          5. The whale shark weighs 30500<\/span> kilograms. The basking shark weighs 9258<\/span> kilograms. Estimate how much more the whale shark weighs.<\/li>\n
                          6. In India there were 155204<\/span> post offices in 2007. In China there were 59886<\/span> post offices. Estimate the difference.<\/li>\n
                          7. By 2008, the Montreal Canadiens had played the most games 5792<\/span>. The Buffalo Sabres had played 2952<\/span>. Estimate how many more games the Montreal Canadiens had played.<\/li>\n
                          8. In 2006, the population of Kelowna was 162276<\/span>. The population of Prince George was 83225<\/span>. Estimate how many more people live in Kelowna in 2006.<\/li>\n<\/ol>\n

                            Answers to Exercise Two<\/strong><\/p>\n

                              \n
                            1. $9000<\/span> \u2212 $7000 = $2000<\/span><\/span><\/li>\n
                            2. 5000<\/span> \u2212 3000<\/span> = 2000<\/span> passengers<\/li>\n
                            3. 50000<\/span> \u2212 30000<\/span> = 20000<\/span> tons<\/li>\n
                            4. 2000<\/span> \u2212 1000<\/span> = 1000<\/span> species<\/li>\n
                            5. 31000<\/span> \u2212 9000<\/span> = 22000<\/span> kilograms<\/li>\n
                            6. 160000<\/span> \u2212 60000<\/span> = 100000<\/span> post offices<\/li>\n
                            7. 6000<\/span> \u2212 3000<\/span> = 3000<\/span> games<\/li>\n
                            8. 160000<\/span> \u2212 80000<\/span> = 80000<\/span> people<\/li>\n<\/ol>\n<\/div>\n<\/div>\n

                              Topic E: Self-Test<\/h1>\n

                              Mark\u00a0 \u00a0 \/18\u00a0\u00a0\u00a0 Aim 14\/18<\/strong><\/p>\n

                                \n
                              1. Estimate the differences.\u00a0 Show your work. (12 marks)\n
                                  \n
                                1. [latex]\\begin{array}[t]{rr}&73\\\\-&34\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                2. [latex]\\begin{array}[t]{rr}&67\\\\-&18\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                3. [latex]\\begin{array}[t]{rr}&896\\\\-&385\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                4. [latex]\\begin{array}[t]{rr}&467\\\\-&214\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                5. [latex]\\begin{array}[t]{rr}&4\\,071\\\\-& 2\\, 986\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                6. [latex]\\begin{array}[t]{rr}&5 \\,946 \\\\-& 4 \\,281\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                7. [latex]\\begin{array}[t]{rr}&57\\, 201\\\\-& 5 \\,892\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                8. [latex]\\begin{array}[t]{rr}&23 \\,006\\\\-& 4 \\,999\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                9. [latex]\\begin{array}[t]{rr}&49 \\,053\\\\-& 28 \\,954\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                10. [latex]\\begin{array}[t]{rr}&36 \\,174\\\\-& 16\\,925\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                11. [latex]\\begin{array}[t]{rr}&86 \\,502 \\\\-& 26 \\,590\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n
                                12. [latex]\\begin{array}[t]{rr}&943 \\,982 \\\\-& 721\\, 354\\\\ \\hline \\\\ \\end{array}[\/latex]<\/li>\n<\/ol>\n<\/li>\n
                                13. Estimate each of the following word problems. (6 marks) Be sure to include the unit of measure in your answer. (2 marks each) Be sure to circle <\/span> information and underline<\/span> what is being asked.\n
                                    \n
                                  1. A magazine has 54823<\/span> readers. Last year the magazine had 26876<\/span> readers. By how much did number of readers increase?<\/li>\n
                                  2. In 2009, the number of marriages per year in Japan was 964702<\/span>. The number of marriages per year in Egypt was 525412<\/span>. How many more marriages were there in Japan than Egypt?<\/li>\n
                                  3. In 2010, in France there were 235846<\/span> people with the last name Martin. There were 78177<\/span> people with the last name Moreau. How many more Martins were there?<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n

                                    Answers to Topic E Self-Test<\/h2>\n
                                      \n
                                    1. \n
                                        \n
                                      1. 40<\/li>\n
                                      2. 50<\/li>\n
                                      3. 500<\/li>\n
                                      4. 300<\/li>\n
                                      5. 1000<\/span><\/li>\n
                                      6. 2000<\/span><\/li>\n
                                      7. 51000<\/span><\/li>\n
                                      8. 18000<\/span><\/li>\n
                                      9. 20000<\/span><\/li>\n
                                      10. 20000<\/span><\/li>\n
                                      11. 60000<\/span><\/li>\n
                                      12. 200000<\/span><\/li>\n<\/ol>\n<\/li>\n
                                      13. \n
                                          \n
                                        1. 20000<\/span> readers<\/li>\n
                                        2. 500000<\/span> marriages<\/li>\n
                                        3. 160000<\/span> Martins<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n","protected":false},"author":90,"menu_order":5,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-69","chapter","type-chapter","status-publish","hentry"],"part":59,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapters\/69","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/wp\/v2\/users\/90"}],"version-history":[{"count":14,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapters\/69\/revisions"}],"predecessor-version":[{"id":789,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapters\/69\/revisions\/789"}],"part":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/parts\/59"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapters\/69\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/wp\/v2\/media?parent=69"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/pressbooks\/v2\/chapter-type?post=69"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/wp\/v2\/contributor?post=69"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/alfm2\/wp-json\/wp\/v2\/license?post=69"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}