Page 105 - Math Smart - 7
P. 105
Example 1
There are 220 pupils in Stage 7. They are going on a school trip.
The buses that they are using have a maximum capacity of 50 people each. How
many buses are needed?
220 4- 50 = 4.4
We cannot say that we need 4.4 buses since we count buses in whole numbers.
Since the digit in the tenths place is 4, 4.4 Is usually rounded down to 4. But what
happens when we only have 4 buses?
4 X 50 = 200. 4 buses can only sit 200 pupils. 20 pupils would be left behind.
In this case, we need to round 4.4 up to 5 In order to fit 220 pupils.
So, 5 buses are needed.
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Understanding
O Mrs Sng needs 6.2 balls of wool to knit a jersey. Each ball of wool costs
$3.15. What Is the total cost of the wool for the jersey?
© You have 12.4 m of red ribbon and 4.8 m of green ribbon. Show how
you would estimate the total length of ribbon you have altogether by
rounding to the nearest metre.
O Kla has 78 sweets. She wants to pack the sweets Into boxes to sell. She
packs 5 sweets into each box. How many boxes will Kla have?
