Page 13 - 新思维数学活动用书6 样章
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1 The number system
1.2 Rounding decimal numbers
Worked example 2
Neve has four number cards. nearest
round
0.25 1.25 2.25 3.25
She chooses two cards.
She adds the numbers on the cards together.
She rounds the result to the nearest whole number.
Her answer is 4.
Which two cards did she choose?
0.25 + 0.25 = 0.5 Look for two numbers that total 3.5 because 3.5 rounds
0.5 rounds up to 1. up to 4.
1.25 and 2.25
or
0.25 and 3.25 You could choose 1.25 and 2.25 or 0.25 and 3.25.
You are specialising when you choose two numbers and check if the total rounds to 4.
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