Page 141 - NUMINO Challenge_C2

Answer Key

Number and Operations Problem solving

1 The last two digits of the result: product of the

1 Various Methods of Multiplication p.8~p.9 ones digits

The first two digits of the result: (product of the

Example 8, 8, 100, 1,000, 100,000 tens digits) (ones digit)
86, 4,386
48 92

68 12

3264 1104

Try It Again 5 32 125 5 4 8 125 468 88 912 22

20 1,000 2 19 12 100 110 18 228

20,000 14 18 100 120 32 252

125 79 125 (80 1)

10,000 125

9,875 Type 1-2 Egyptian Multiplication p.12~p.13

Answers will vary.

123 24 18
24 1
Example 53 53 48 2
3 96 4
4 1 0 3 192 8
5 9 384 16
432 18 2 16
2 1 4
0 2 48 384 432

53 , 1,802

1 0 9 3
5
1

8 2 1 4
0 2

02

Problem solving

Type 1-1 Easy Multiplication p.10~p.11 1

1 Since 7 3 21, 8 2 16, and 5 5 25, the 21 31 651 6
results are the products of the ones digits. 51

2 Since (3 1) 3 12, (6 1) 6 42, and 2 23 52 18 25
(7 1) 7 56, the first two digits follow the rule
of {(1st number) 1} (1st number). 23 1 18 1

46 2 36 2

3 84 86 7224 55 55 3025 92 4 72 4
(8 1) 8 72 (5 1) 5 30
4 6 24 5 5 25 184 8 144 8

368 16 288 16

736 32 450 25

1,196 52 1 8 16 25

4 16 32 52 18 144 288 450

92 368 736 1,196

NUMINO Challenge C2