The 5 steps below will quickly show you how to multiply using partial products. Here, we will do the multiplication for a two-digit number by another two-digit number. For example, the figure below shows how to quickly multiply 26 by 45.
If you did not quite understand the example in the figure below, keep reading since we broke the multiplication down into 5 steps.
If you multiply a two-digit number by another two-digit number, you will have 4 partial products.
Step 1
Tens Ones
4 5
x 2 6
__________
8 0 0 <---------- partial product
Multiply the tens by the tens: 2 tens x 4 tens = 20 x 40 = 800.
Step 2
Tens Ones
4 5
x 2 6
__________
1 0 0 <---------- partial product
Multiply the ones by the tens: 5 ones x 2 tens = 5 x 20 = 100.
Step 3
Tens Ones
4 5
x 2 6
__________
2 4 0 <---------- partial product
Multiply the tens by the ones: 4 tens x 6 ones = 40 x 6 = 240
Step 4
Tens Ones
4 5
x 2 6
__________
3 0 <---------- partial product
Multiply the ones by the ones: 5 ones x 6 ones = 30 ones = 30
Step 5
Tens Ones
4 5
x 2 6
__________
8 0 0
1 0 0
2 4 0
3 0
_________
1 1 7 0
Just add the four partial products to get the answer: 800 + 100 + 240 + 30 = 1170
So, 26 x 45 = 1170