the trick math

multiplication

100

40x26

1040

200

30x2

60

300

125x6

750

400

260x45

11700

500

432x74

31968

Divide

100

70/10

7

200

50/5

10

300

35/7

5

400

256/8

32

500

684/44

1.5

multiplication 2

100

1x2

2

200

3x10

30

300

9x100

900

400

94x87

8178

500

186x89

16554

rounding

100

645

650

200

1564

2500

300

6946

7900

400

4960

5000

500

7856

7900

Divide

100

50/10

5

200

70/10

7

300

40/10

4

400

789/54

14

500

78/54

1.4