Multiply of 37 by multiplies of 3:


3 x 37 = 111

6 x 37 = 222

9 x 37 = 333

12 x 37 = 444

15 x 37 = 555

18 x 37 = 666

21 x 37 = 777

24 x 37 = 888

27 x 37 = 999



Nice one:

111.111.111 x 111.111.111 = 12.345.678.987.654.321



Trapeze:

1 x 9 + 2 = 11

12 x 9 + 3 = 111

123 x 9 + 4 = 1111

1234 x 9 + 5 = 11111

12345 x 9 + 6 = 111111

123456 x 9 + 7 = 1111111

1234567 x 9 + 8 = 11111111

12345678 x 9 + 9 = 111111111


another Trapeze:

1 x 8 + 1 = 9

12 x 8 + 2 = 98

123 x 8 + 3 = 987

1234 x 8 + 4 = 9876

12345 x 8 + 5 = 98765

123456 x 8 + 6 = 987654

1234567 x 8 + 7 = 9876543

12345678 x 8 + 8 = 98765432

123456789 x 8 + 9 = 987654321


and another one:

0 x 9 + 8 = 8

9 x 9 + 7 = 88

98 x 9 + 6 = 888

987 x 9 + 5 = 8888

9876 x 9 + 4 = 88888

98765 x 9 + 3 = 888888

987654 x 9 + 2 = 8888888

9876543 x 9 + 1 = 88888888

98765432 x 9 + 0 = 888888888

987654321 x 9 - 1 = 8888888888

9876543210 x 9 - 2 = 88888888888

原來數學也能很有趣^^