Chapter 1. Using model diagrams to solve simple problems

Problem 1

John has 7 balls. Mark has 5 balls more than John. How many balls does Mark have?

Solution

Draw a box to represent the 7 balls John has and a bigger box to represent that Mark has 5 more balls than John.

Number of balls Mark has = 7 + 5 = 12

Problem 2

John has 6 balls. Mark has 2 times as many balls as John. How many balls does Mark have?

Solution

Draw a box to represent the 6 balls John has and another two boxes of the same size to represent the number of balls Mark has.

Number of balls Mark has = 2 x 6 = 12

Problem 3

John has 6 balls. Mark has 3 times as many balls as John. How many balls does Mark have?

Solution

Draw a box to represent the 6 balls John has and another three boxes of the same size to represent the number of balls Mark has.

Number of balls Mark has = 3 x 6 = 18

Worksheet

1. Jim has 9 apples. Jenny has 8 apples more than Jim. How many apples does Jenny have?

2. Jim has 8 apples. Jenny has 4 times as many apples as Jim. How many apples does Jenny have?

3. Jim has 7 apples. Jenny has 5 times as many apples as Jim. How many apples does Jenny have?

4. Jim has 13 pears. Jenny has 6 pears less than Jim. How many pears does Jenny have?