Page 21 - 新思维数学学生用书3 样章

1 Numbers to 1000

4 Round each number to the nearest 100.

123 678 385

907 740 598

If the numbers in questions 3 and 4 were dollars ($), grams

or kilometres, could you round them to the nearest 10 or
100 dollars ($), grams or kilometres?

5 Which number in questions 3 and 4 rounds to the same number
when rounded to the nearest 10 and to the nearest 100?

Think like a mathematician

When a number is rounded to the nearest 10 and the same number is

rounded to the nearest 100, the answer is the same. What could the
number be?

Sofia includes 100, 200, 300, 400, 500, 600, 700, 800, 900 and

1000 in her list of numbers. Do you agree with her? Why?

Look what I can do!

I can estimate quantities by giving a range of numbers

as an estimate.
I can round numbers to the nearest 10.

I can round numbers to the nearest 100.

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