Show:
1 digit by 1 digit
2 digit by 2 digit
100

5 x 5

25

100

12 x 12

144

200

6 x 5

30

200

3 x 50

150

300

4 x 3

12

300

40 x 50

2000

400

7 x 2 

14

400

30 x  30

900

500

2 x 9

18

500

12 x 11

132