Mark Symmonds – Chatsworth International School, Singapore
Just like when we count, start from the left. 1, 2, 3, 4, 5, 6…
As we are looking for 3 multiplied by 9 we count across to our 3 rd finger and move it down
Marker Finger 3 x 9 = 1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45
Marker Finger 7 x 9 = 1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45 6 x 9 = 54 7 x 9 = 63 8 x 9 = 72 9 x 9 = x 9 = 90
Marker Finger 9 x 9 = 1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45 6 x 9 = 54 7 x 9 = 63 8 x 9 = 72 9 x 9 = x 9 = 90
1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45 6 x 9 = 54 7 x 9 = 63 8 x 9 = 72 9 x 9 = x 9 = x 9 = x 9 = 108
Remember there are no tens digit in 1 x 9 as the answer is 0 tens and 9 units! The tens digit is always one less than the number you are dividing! This pattern only works up until 10 x 9
1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45 6 x 9 = 54 7 x 9 = 63 8 x 9 = 72 9 x 9 = x 9 = x 9 = x 9 = added to nothing equals 9
If you add both the digits of the answer together they will always equal 9. The tens column in the answer is always one less than the one you are multiplying. So if we take 7 x 9… We know the answer will start with? So we know that the answer is 63. And the two digits added together make nine so 6 and what make 9? 3 6
so… 1980 so…
so… 5445 so…
so… so…