Page 15 - 新思维数学学生用书5 样章

1 The number system

Can you round these heights to the nearest whole number?

Height of elephant 3.3 m Height of giraffe 5.5 m

How tall are you?

Height of ostrich 2.7 m

Worked example 2

Round these measurements to the nearest whole number.

a 3.9 m b 4.5 m c 0.4 m

You can use a number line to help you.

0 1 2 3 4 5
Answer: If the tenths digit is 0, 1, 2, 3 or 4, round down to the nearest

a 4 m whole number.
b 5 m If the tenths digit is 5, 6, 7, 8 or 9, round up to the nearest

c 0 m whole number.

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