Page 17 - 新思维数学活动用书7 样章

1 Integers

2 Work out:
a 64 b 100 c 225 d 169
3 Work out:
a 1 + 2 3 b 3 + 5 3 c 4 − 2 3
3
3
3
4 Work out:
a 64 − 3 64 b 25 − 3 125 c 3 27 − 16
5 Work out:
a 3 216 b 3 512 c 3 1000 d 3 1728

Practice

6 Copy and complete:
a =20 b =25 c =30 d =35

7 Copy and complete:
a 3 = 6 b 3 = 10 c 3 = 11 d 3 = 15

8 Find the integer that is closest to:
a 38 b 220 c 3 70

9 45 is between 6 and 7.

Write down a similar statement for:

a 90 b 135

10 Mustafa thinks of a number. The number is between 100 and 200. The square root of the
number is a multiple of 3.
What is Mustafa’s number?
11 a Find all the numbers between 100 and 200 that have an integer square root.

b Find all the numbers between 100 and 200 that have an integer cube root.

Challenge

12 Find the highest common factor of 1 + 2 + 3 and 4 + 5 + 6 .
2
2
2
2
2
2
13 Jiale thinks of a number. She works out the square root of the number. Then she works out the
cube root of the square root of the number. The answer is 2.
a Find Jiale’s number.
b Show that Jiale gets the same answer if she finds the cube root first and then the square root.

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