Show:
multiplying by 12s
multiplying by 20s
multiplying by 10s
multiplying by 5s
multiplying by 7s
100

12x4

48

100

20x22

440

100

10x0

0

100

5x12

60

100

7x3

21

200

12x6

72

200

20x13

260

200

10x1

10

200

5x10

50

200

7x7

49

300

12x2

24

300

20x10

200

300

10x3

30

300

5x8

40

300

7x5

35

400

12x10

120

400

20x12

240

400

10x100

1000

400

5x100

500

400

7x10

70

500

12x7

84

500

20x2

40

500

10x6

60

500

5x13

65

500

7x21

147