Here we will show you step-by-step how to calculate 12 plus 21 (12 + 21) using the Long Addition Method. We start by setting up our math problem as follows:
| 1 | 2 | |||||||
| + | 2 | 1 | ||||||
The next step is to add the ones digits together (2 + 1 = 3) like this:
| 1 | 2 | |||||||
| + | 2 | 1 | ||||||
| 3 |
Then in our final step, we add the tens digits together (1 + 2 = 3) like this:
| 1 | 2 | |||||||
| + | 2 | 1 | ||||||
| 3 | 3 |
And that is how you solve 12 plus 21 using the Long Addition Method! The answer is displayed mathematically below:
12 + 21 = 33
Long Addition Calculator
Here you can enter another addition problem for us to explain and solve using the Long Addition Method: