Chapter 2: Mental Math Page 1

62 Chapter 2: Numeration Copyright © 2004 Nelson

Name: Date:

1. Find the missing numbers in each number pattern.

a) 18, 19, , 21, 22, , d) 33, 32, 31, , ,

b) 88, 89, , , 92, 93 e) 60, 55, 50, , ,

c) 20, 30, 40, , , f) 100, 90, 80, , ,

2. How many pairs of hands with 10 fingers in total are needed to make these numbers?

a) 20 b) 40 c) 50 d) 90 e) 100

3. How many hundreds blocks are needed to make these numbers?

a) 500 b) 900 c) 600 d) 400

4. Write the numeral for each.

a) = d) 100 + 100 + 100 =

b) 20 + 10 + 10 + 5 = e) 100 + 20 + 5 =

c) 400 + 9 = f) 600 + 1 =

5. Round each pair of numbers to the nearest ten. Add the two rounded numbers in your head.

a) 12 and 13 d) 48 and 29

b) 18 and 19 e) 54 and 43

c) 25 and 28 f) 68 and 29

6. Circle the greater number in each pair.

a) 50 20

b) 28 42

c) 45 + 5 30 + 30

d) 20 + 20 + 20 50 + 9

e) 100 + 100 100 + 50

f) 100 – 10 90 + 5

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Chapter 2: Mental Math Page 2

63Blackline MastersCopyright © 2004 Nelson

Name: Date:

7. Write the numeral for each.

a) = d) 500 + 60 + 10 =

b) 100 + 20 + 5 = e) 100 + 200 + 100 + 20 + 5 =

c) 400 + 10 + 6 = f) 20 + 10 + 4 =

8. Here are the times of 6 runners in a race:60 seconds 48 seconds 55 seconds 40 seconds 53 seconds 65 seconds

a) Put the times in order from fastest to slowest.

b) Use mental math to find the difference between the slowest time and the fastest time.

9. Add these money amounts in your head. Write the answer in cents using the symbol ¢.

a) b) c)

10. Use combinations of the numbers 5, 10, 20, 50, or 100 and the + symbol to make these numbers. You can use the same numbers more than once.

a) 15 b) 35 c) 160

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