Show:
Estimating
2 Digit By 1
2 by 2
Multiply with 0's
100

33 x 21

600

100

33 x 2

66

100
11 x 22

242

100

20 x 10

200

200

51 x 38

2000

200

45 x 5

225

200

25 x 31

775

200

50 x 30

1500

300

78 x 84

6400

300

67 x 7

469

300

52 x 51

2652

300

70 x 90

6300

400

93 x 47

4500

400

58 x 9

522

400

78 x 62

4836

400

20 x 300

6000

500

99 x 49

5000

500

98 x 8

784

500

77 x 59

4543

500

700 x 600

420000