Word Problems in Fractions 2

Multiplication

Multiplication problems are more realistic, as long as we use simple fractions. We saw that the subtraction problem in the previous chapter would be more realistic as a multiplication problem. The problem to illustrate ¾ X ½ can be restated as shown below.

Ram’s mother bought a chocolate bar and gave him 3/4thof the cake to take to school. Ram gave away half his share to his friends. How much of the original chocolate does he have for himself?

Solution – Assume that the bar had 8 portions. He took 6 pieces to school. He gave 3 (1/2 of 6) portions to his friends and so he had 3 portions for himself. So he had 3/8 th of the original chocolate bar for himself.

Division

Let us take ¾ ÷ 1/8. A typical problem would be as follows.

Ram’s mother gave him a packet of toffees. She gave him 3/4thof the packet. He took it to school and gave some of his friends 1/8thof the original packet each. How many friends got toffees from him?

Solution – Let us assume that the packet contained 24 toffees. So Ram got 18 (3/4thof 24) toffees to take to school. He gave his friends 3 toffees (1/8thof 24) each. Hence 6 friends (18 ÷ 3) got toffees from him. Hence ¾ ÷ 1/8 should be 6. Applying the fraction division procedure also we get the answer as 6.

We can see that such a real-life situation is very unrealistic.

1. A plot of land is ¾ of an acre. It has to be divided into plots of 1/8 acre each. How many plots would we get?

2. We have 5 3/8 meters of cloth. Each shirt needs 1 ¼ of a meter. How many shirts can be made?