EG1) 45 x 67
You have a small number colum and a big number colum. On the small number colum you keep 1/2 the numbers ignoring the remainders until you get to 1. On the big number colum you keep doubling.
Small Big
45 67
22 134
11 268
5 536
2 1072
1 2144
You cross out all the even numbers in the small colum and cross out their partners. I will put the ones that are suppose to be crossed out in a different colour.
Small Big
45 67
22 134
11 268
5 536
2 1072
1 2144
All the numbers in the big colum that haven't been crossed out you add together and that is your answer to the sum.
67 + 268 + 536 + 2144 = 3015
45 x 67 = 3015
Questions :
1. 24 x 36
2. 420 x 12
3. 276 x 12
You have a small number colum and a big number colum. On the small number colum you keep 1/2 the numbers ignoring the remainders until you get to 1. On the big number colum you keep doubling.
Small Big
45 67
22 134
11 268
5 536
2 1072
1 2144
You cross out all the even numbers in the small colum and cross out their partners. I will put the ones that are suppose to be crossed out in a different colour.
Small Big
45 67
22 134
11 268
5 536
2 1072
1 2144
All the numbers in the big colum that haven't been crossed out you add together and that is your answer to the sum.
67 + 268 + 536 + 2144 = 3015
45 x 67 = 3015
Questions :
1. 24 x 36
2. 420 x 12
3. 276 x 12