This is the easiest way to teach your kids how to multiply by 9!
Instructions:
1. Write the multiplication of 9
2. Write the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 from top to bottom and beside them
3. Write the numbers 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 from top to bottom as shown below
A M A Z I N G, isn't it?
Did you know?
That if you multiply nine by any natural number, and repeatedly add the digits
of the answer until it is just one digit, you will end up with nine:
2 × 9 = 18 (1 + 8 = 9)
3 × 9 = 27 (2 + 7 = 9)
9 × 9 = 81 (8 + 1 = 9)
121 × 9 = 1089 (1 + 0 + 8 + 9 = 18; 1 + 8 = 9)
234 × 9 = 2106 (2 + 1 + 0 + 6 = 9)
578329 × 9 = 5204961 (5 + 2 + 0 + 4 + 9 + 6 + 1 = 27; 2 + 7 = 9)
482729235601 × 9 = 4344563120409 (4 + 3 + 4 + 4 + 5 + 6 + 3 + 1 + 2 + 0 + 4 + 0 + 9 = 45; 4 + 5 = 9)
3 × 9 = 27 (2 + 7 = 9)
9 × 9 = 81 (8 + 1 = 9)
121 × 9 = 1089 (1 + 0 + 8 + 9 = 18; 1 + 8 = 9)
234 × 9 = 2106 (2 + 1 + 0 + 6 = 9)
578329 × 9 = 5204961 (5 + 2 + 0 + 4 + 9 + 6 + 1 = 27; 2 + 7 = 9)
482729235601 × 9 = 4344563120409 (4 + 3 + 4 + 4 + 5 + 6 + 3 + 1 + 2 + 0 + 4 + 0 + 9 = 45; 4 + 5 = 9)
One more interesting pattern involving multiples of nine:
12345679 x 9 = 111111111
12345679 x 18 = 222222222
12345679 x 81 = 999999999
More number tricks:
Impressive Number Trick - The Printing Press Number
The Number 5 Trick
12345679 x 18 = 222222222
12345679 x 81 = 999999999
More number tricks:
Impressive Number Trick - The Printing Press Number
The Number 5 Trick
Made by Greg Dallas for tapandaola111.blogspot.com
