Multiply Double-Digits by Any Other Double-Digits
The cool thing about math is watching how seemingly impossible combinations seem to walk out perfectly in the end. By doing certain operations, you can turn wildly complex equations into simple, step-by-step solutions.
Using the Vertical and Crosswise Pattern, we can easily multiply large two-digit numbers like the one pictured below.
Instead of doing the standing method of multiplication, we are going to separate and conquer.
12 x 34
First, we multiply vertically up the right side. 2 x 4 = 8. So, 8 will be the last digit in our answer.
Next, we cross-multiply. 3 x 2 = 6 and 4 x 1 = 4. Now add 6 + 4 to get 10. Carry over the 1 like you normally would, and you are left with 0, which will go in front of the 8 we already have.
So, as of now you should have 08 in you answer line.
Lastly, we vertically multiply up the left side. 3 x 1 = 3 and add the carried 1. Place that in the front of our answer line and we get 408.