Question

To find 12 times 13, I double 13 and halve 12 and then multiply

Answer 1

No just multiply them 12 times 12 is 144 just add 12 so it could be 12 times 13 and it would be 156

Answer 2

13
x12
——-
26
+130
——-
156

So first you do the back of 12, 2 times the back of 13, which is 6. Then the back of 12, 2 times the front of 13, which is 2. So you get 26. Then you go to the next line and put a zero, then the same thing as you did with the back of 12, but with the front, which is 1. So 1 times 3 and 1 times 1, so you get 13 and the zero you added earlier, 130. So you get 26 and 130, add them to get 156.