[ابن الحته]

1×8+1=9

12×8+2=98

123×8+3=987

1234×8+4=9876

12345×8+5=98765

123456×8+6=987654

1234567×8+7=9876543

12345678×8+8=98765432

123456789×9+9=987654321

.........................

9 × 9 = 81

98 × 9 = 882
987 × 9 = 8883

9876 × 9 = 88884
98765 × 9 = 888885
987654 × 9 = 8888886
9876543 × 9 = 88888887
98765432 × 9 = 888888888

987654321 × 9 = 8888888889

من عجائب الرقم 9 أيضاً ما نلاحظه هنا :

123456789× 9 = 1111111101
12345678 × 9 = 111111102
1234567 × 9 = 11111103
123456 × 9 = 1111104
12345 × 9 = 111105
1234 × 9 = 11106
123 × 9 = 1107
12 × 9 = 108
1 × 9 = 09

أيضاً :

9×0+1=1

9×1+2=11

9×12+3=111

9×123+4=1111

9×1234+5=11111

9×12345+6=111111

9×123456+7=1111111

9×1234567+8=11111111

9×12345678+9=111111111

عجائب الرقم

8 و 9

0×9+8=8
9×9+7=88
98×9+6=888
987×9+5=8888
9876×9+4=88888
98765×9+3=888888
4 98765×9+2=8888888
9876543×9+1=88888888
98765432×9+0=888888888