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

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.

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