647 plus 284 equals what?
Our first step is to line these two numbers up on top of each other, making sure their units are all lined up. The ones place are lined up with the ones place. The tens place are lined up with the tens place. And the hundreds place is lined up with the hundreds place.
Now we’re ready to add them together. We start all the way on the right with the units place. And we say seven plus four equals 11. We write down the one. And then we carry the other one into the tens place. In the tens place, we’ll add one plus four plus eight. One plus four is five, and five plus eight is 13. So we write down our three. And we carry our one. Now we move on to the hundreds place, where we add one plus six plus two. One plus six is seven, plus two — seven plus two equals nine. Using the standard algorithm, we found that 647 plus 284 equals 931.