ACTIVITY 6

Example: Refilwe loves to play with marbles. She has 12 marbles in her marble bag. During a competition, she loses 3 marbles. How many does she have left?

12 – 3 = ?

If you solve the number sentence:

12 – 3 = 9

Refilwe has 9 marbles left.

Write a few number sentences on your own.

1. Write a number sentence for each of the statements or questions.

1.1 Mr Smith has 6 pencils. He picks up another 2 pencils on the playground. How many pencils does Mr Smith have altogether?

1.2 4 red birds sit on a branch. After a little while, 6 blue birds arrive and also sit on the branch. How many birds are sitting on the branch now?

1.3 Lilly has 9 sweets. Lucy does not have any sweets. How many more sweets does Lilly have than Lucy?

1.4

1.5 Jo has 3 cards less than James. James has 18 cards. How many cards does Jo have?

Question

Luke puts 15 flowers in a vase. 5 of the flowers wilt. How many flowers does Luke have left?

Answer

6 + 2 = 8

4 + 6 = 10

9 – 0 = 9

15 – 5 = 10

18 – 3 = 15

Number sentences are not only represented with words, but can also be shown without using any words.

You can solve and complete number sentences by: • inspection • trial and improvement • checking the solution by substitution

Let us look at solving number sentences by inspection.

The inspection method is another name for ‘guess the answer’. If you look at a number sentence and must find the answer without making calculations, you will use the inspection method. In maths we only solve simple number sentences by inspection.