# Topic B: Addition of Three or More Numbers

To add three or more numbers together, use the following steps.

1. Add the first two numbers together.
2. Add that sum to the next number.
3. Add that sum to the next number (if needed).

Example A:

\begin{align} 6\\ 1\\ +3\\ \hline \\ \end{align}

1. Add the first two numbers together.
\begin{align} 6 \\ +1\\ \hline 7 \end{align}
2. Add that sum to the next number.
\begin{align} 7\\ +3 \\ \hline 10 \end{align}

The sum of:

\begin{align} 6 \\ 1\\ +3\\ \hline 10 \end{align}

Example B:

\begin{align} 4\\ 5\\ +7\\ \hline \\ \end{align}

1. Add the first two numbers together.
\begin{align} 4\\ +5\\ \hline 9 \end{align}
2. Add that sum to the third number.
\begin{align} 9\\ +7\\ \hline 16 \end{align}

The sum of:

\begin{align} 4\\ 5\\ +7\\ \hline 16 \end{align}

Exercise 1

Find the sums. Check your work using the answer key at the end of the exercise.

1. \begin{align} 1\\ 2\\ +5\\ \hline \\ \end{align}
2. \begin{align} 6\\ 3\\ +2\\ \hline \\ \end{align}
3. \begin{align} 7\\ 1\\ +6\\ \hline \\ \end{align}
4. \begin{align} 3\\ 6\\ +5\\ \hline \\ \end{align}
5. \begin{align} 8\\ 1\\ +4\\ \hline \\ \end{align}
6. \begin{align} 5\\ 4\\ +8\\ \hline \\ \end{align}
7. \begin{align} 1\\ 5\\ +7\\ \hline \\ \end{align}
8. \begin{align} 7\\ 2\\ +5\\ \hline \\ \end{align}
9. \begin{align} 1\\ 8\\ +3\\ \hline \\ \end{align}
10. \begin{align} 4\\ 5\\ +9\\ \hline \\ \end{align}
11. \begin{align} 2\\ 2\\ +8\\ \hline \\ \end{align}
12. \begin{align} 6\\ 3\\ +5\\ \hline \\ \end{align}
13. \begin{align} 7\\ 2\\ +5\\ \hline \\ \end{align}
14. \begin{align} 3\\ 2\\ +5\\ \hline \\ \end{align}
15. \begin{align} 6\\ 2\\ +5\\ \hline \\ \end{align}
16. \begin{align} 4\\ 4\\ +5\\ \hline \\ \end{align}

Answers to Exercise 1

1. 8
2. 11
3. 14
4. 14
5. 13
6. 17
7. 13
8. 14
9. 12
10. 18
11. 12
12. 14
13. 14
14. 10
15. 13
16. 13

Exercise 2

Find the sums. Check your work using the answer key at the end of the exercise.

1. \begin{align} 3\\ 5\\ +7\\ \hline \\ \end{align}
2. \begin{align} 2\\ 6\\ +8\\ \hline \\ \end{align}
3. \begin{align} 4\\ 1\\ +9\\ \hline \\ \end{align}
4. \begin{align} 5\\ 4\\ +2\\ \hline \\ \end{align}
5. \begin{align} 3\\ 6\\ +4\\ \hline \\ \end{align}
6. \begin{align} 2\\ 5\\ +4\\ \hline \\ \end{align}
7. \begin{align} 6\\ 3\\ +2\\ \hline \\ \end{align}
8. \begin{align} 3\\ 5\\ +3\\ \hline \\ \end{align}
9. \begin{align} 3\\ 4\\ +7\\ \hline \\ \end{align}
10. \begin{align} 4\\ 5\\ +9\\ \hline \\ \end{align}
11. \begin{align} 6\\ 3\\ +2\\ \hline \\ \end{align}
12. \begin{align} 5\\ 2\\ +9\\ \hline \\ \end{align}

Answers to Exercise 2

1. 15
2. 16
3. 14
4. 11
5. 13
6. 11
7. 11
8. 11
9. 14
10. 18
11. 11
12. 16

Exercise 3

Find the sums. Check your work using the answer key at the end of the exercise.

1. \begin{align} 3\\ 2\\ +8\\ \hline \\ \end{align}
2. \begin{align} 2\\ 1\\ +4\\ \hline \\ \end{align}
3. \begin{align} 4\\ 3\\ +1\\ \hline \\ \end{align}
4. \begin{align} 1\\ 2\\ +8\\ \hline \\ \end{align}
5. \begin{align} 3\\ 2\\ +2\\ \hline \\ \end{align}
6. \begin{align} 5\\ 1\\ +2\\ \hline \\ \end{align}
7. \begin{align} 7\\ 2\\ +8\\ \hline \\ \end{align}
8. \begin{align} 4\\ 2\\ +6\\ \hline \\ \end{align}
9. \begin{align} 7\\ 2\\ +7\\ \hline \\ \end{align}
10. \begin{align} 6\\ 1\\ +1\\ \hline \\ \end{align}
11. \begin{align} 2\\ 7\\ +6\\ \hline \\ \end{align}
12. \begin{align} 3\\ 4\\ +2\\ \hline \\ \end{align}
13. \begin{align} 3\\ 4\\ +1\\ \hline \\ \end{align}
14. \begin{align} 7\\ 1\\ +9\\ \hline \\ \end{align}
15. \begin{align} 2\\ 6\\ +4\\ \hline \\ \end{align}
16. \begin{align} 3\\ 1\\ +2\\ \hline \\ \end{align}

Answers to Exercise 3

1. 13
2. 7
3. 8
4. 11
5. 7
6. 8
7. 17
8. 12
9. 16
10. 8
11. 15
12. 9
13. 8
14. 17
15. 12
16. 6

Exercise 4

Find the sums. Check your work using the answer key at the end of the exercise.

1. \begin{align} 1\\ 3\\ 4\\ +5\\ \hline \\ \end{align}
2. \begin{align} 2\\ 3\\ 4\\ +6\\ \hline \\ \end{align}
3. \begin{align} 4\\ 3\\ 2\\ +8\\ \hline \\ \end{align}
4. \begin{align} 3\\ 1\\ 5\\ +6\\ \hline \\ \end{align}
5. \begin{align} 2\\ 2\\ 3\\ +2\\ \hline \\ \end{align}
6. \begin{align} 3\\ 3\\ 1\\ +2\\ \hline \\ \end{align}
7. \begin{align} 2\\ 1\\ 2\\ +4\\ \hline \\ \end{align}
8. \begin{align} 1\\ 2\\ 4\\ +6\\ \hline \\ \end{align}
9. \begin{align} 2\\ 4\\ 1\\ +6\\ \hline \\ \end{align}
10. \begin{align} 3\\ 2\\ 3\\ +3\\ \hline \\ \end{align}
11. \begin{align} 2\\ 1\\ 4\\ +0\\ \hline \\ \end{align}
12. \begin{align} 3\\ 1\\ 4\\ +1\\ \hline \\ \end{align}

Answers to Exercise 4

1. 13
2. 15
3. 17
4. 15
5. 9
6. 9
7. 9
8. 13
9. 13
10. 11
11. 7
12. 9

# Perimeter

Did you spot the fact that each answer in the word problems before had a unit of measure? A unit of measure just tells you what you measured. Units of measure can be pages, fish, cans, kilometres, meters, centimetres, litres, millilitres, grams, or kilograms. When you answer a word problem, you must include the unit of measure in your answer.

Try the following questions. Be sure to include the unit of measure in your answer.

Perimeter means distance around. To find the perimeter of a shape, find the lengths of the sides and add them together.

Example: Rectangle

To find the perimeter, add the lengths of the sides of the rectangle.

• Perimeter = 3 + 2 + 3 + 2
• Perimeter = 10 meters

Exercise 5

Find the perimeter of each figure. Be sure to include the units of measure in your answer. Check your work using the answer key at the end of the exercise.

1. Find the perimeter of the swimming pool.
2. Find the perimeter of the garden.
3. Find the perimeter of the greenhouse.
4. Find the perimeter of the sign.

Answers to Exercise 5

1. 14 metres
2. 13 metres
3. 12 metres
4. 10 metres

# Topic B Self-Test

Mark      /18        Aim      15/18

1. Find the sums. Be sure to check your answers. (12 marks)
1. \begin{align} 4\\ 6\\ +2\\ \hline \end{align}
2. \begin{align} 3\\ 6\\ +9\\ \hline \end{align}
3. \begin{align} 7\\ 2\\ +8\\ \hline \end{align}
4. \begin{align} 2\\ 1\\ +4\\ \hline \end{align}
5. \begin{align} 3\\ 5\\ +8\\ \hline \end{align}
6. \begin{align} 4\\ 6\\ +7\\ \hline \end{align}
7. \begin{align} 3\\ 1\\ 5\\ +2\\ \hline \end{align}
8. \begin{align} 4\\ 2\\ 3\\ +7\\ \hline \end{align}
9. \begin{align} 5\\ 3\\ 1\\ +8\\ \hline \end{align}
10. \begin{align} 3\\ 5\\ 1\\ +3\\ \hline \end{align}
11. \begin{align} 1\\ 5\\ 4\\ +6\\ \hline \end{align}
12. \begin{align} 2\\ 1\\ 6\\ +5\\ \hline \end{align}
2. Solve each of the following word problems. Be sure to include the unit of measure in your answer. Be sure to circle the information and underline what’s being asked.(6 marks, 2 marks each)
1. It took the cleanup crew 4 hours on Monday, 3 hours on Tuesday and 9 hours on Wednesday to clean the factory after each day’s work. How many hours in total did it take to clean the factory?
2. Nella wants to put a fence around her garden. The garden measures 5 metres, 3 metres and 1 metre. How much fence does she need?
3. Find the perimeter of the garden.

Answers to Topic B Self-Test

1. 12
2. 18
3. 17
4. 7
5. 16
6. 17
7. 11
8. 16
9. 17
10. 12
11. 16
12. 14
1. 16 hours
2. 9 metres
3. 12 metres