# 5 - Problems

## Simple problems

Here are 4 examples of simple problems that you have to understand well :

You have 13 dollars, you have been given 9 dollars, how many dollars do you have now ? It is very simple, you have to calculate a sum. 9 + 13 = 22 so you now have 22 dollars.

You have 10 dollars, you have bought an item that costs 1,60 dollars. How much do you have left? To answer this question you have to do a subtraction. 10 - 1,60 = 8,40 you now have 8,40 dollars.

A farmer has 5 hens, each of which lays 6 eggs a week. How many eggs will the farmer get in a week? To answer this question you have to do a multiplication. 5 × 6 = 30 so the farmer will get 30 eggs in a week.

3 children want to share equally 24 small stones. How many stones will each child have? To answer this question you have to do a division. 24 ÷ 3 = 8 so each child will have 8 small stones.

## Problems with several operations

To solve a problem with several operations, you have to understand well the problem and to do the operations ones after the others. Example. A mother goes shopping. She buys chocolate at 4 dollars 20, soap at 9 dollars 45 and pastas at 1 dollars 12. She pays with a 20 dollars note. How much does the shopper have to give her back?
You first have to calculate a sum to know the amount spent : 4,2 + 9,45 + 1,12 = 14,77, then you have to do a subtraction to know how much the shopper has to give her back. 20 - 14,77 = 5,33 so the shopper gives her back 5 dollars 33. Do not hesitate to write down the operations.