Page 18 - 新思维数学学生用书6 样章
P. 18
1.2 Rounding decimal numbers
Check your progress
1 Copy and complete.
87.655 = 80 + 7 + + +
2 What decimal number is represented by the following?
90 + 7 + 3 + 1 + 4
10 100 1000
3 How many times bigger is the value of the digit 6 in 64.53 than the
value of the digit 6 in 0.367?
4 a What is 3.08 rounded to the nearest tenth?
b What is 9.55 rounded to the nearest whole number?
5 Find the missing numbers.
a × 0.9 = 9 b 705 ÷ = 7.05
c × 0.16 = 160 d 34 ÷ 1000 =
6 The announcer said, ‘Ingrid won the 100-metre race in 13.9 seconds.’
Her time was originally measured to 2 decimal places.
What was the slowest time she could have run?
17
