1.2 Interpreting answers when dividing
After carrying out a division calculation you may not have an answer that is suitable.
For example, if you were at a restaurant and needed to split a bill of £126.49 between four people you would first calculate the division £126.49 ÷ 4 = £31.6225. Clearly you cannot pay this exact amount and so we would round it up to £31.63 to make sure the whole bill is covered.
In other situations, you may need to round an answer down. If you were cutting a length of wood that is 2 m (200 cm) long into smaller pieces of 35 cm you would initially do the calculation 200 ÷ 35. This would give an answer of 5.714…. As you will only actually be able to get 5 pieces of wood that are 35 cm long, you need to round your answer of 5.714 down to simply 5.
Note: The three full stops used in the answer above (5.714…) is a character called an ellipsis. In maths it is used to represent recurring decimal numbers so you don’t have to display them all.
Activity 4: Interpreting answers
Calculate the answers to the following. Decide whether the answers need to be adjusted up or down after calculation of the division sum.
Apples are being packed into boxes of 52. There are 1500 apples that need packing. How many boxes are required?
A bag of flour contains 1000 g. Each batch of cakes requires 150 g of flour. How many batches can you make?
A child gets £2.50 pocket money each week. They want to buy a computer game that costs £39.99. How many weeks will they need to save up in order to buy the game?
A length of copper pipe measures 180 cm. How many smaller pieces that each measure 40 cm can be cut from the pipe?
Answer
1500 ÷ 52 = 28.846 which must be adjusted up to 29 boxes.
1000 ÷ 150 = 6.666 which must be adjusted down to 6 batches.
£39.99 ÷ £2.50 = 15.996 which must be adjusted up to 16 weeks.
180 ÷ 40 = 4.5 which must be adjusted down to 4 pieces.