In this activity, we will learn how to add together two three-digit numbers.
Three-digit numbers have hundreds, tens and ones.
One way to add them together is to partition them into their place value.
453 + 429
453 has four hundreds, five tens, and three ones.
429 has four hundreds, two tens, and nine ones.
Once partitioned, we can add the hundreds, tens and ones.
3 + 9 = 12
50 + 20 = 70
400 + 400 = 800
Lastly, we can add together these numbers to find out the total sum.
800 + 70 + 12 = 882
Let's try an example together.
Example
Add the numbers:
628 + 257
Answer
First we add the ones: 8 + 7 = 15
Then we add the tens: 20 + 50 = 70
Then we add the hundreds: 600 + 200 = 800
Lastly, we combine the three results: 800 + 70 + 15 = 885
The answer is 885
Now it's your turn to try some questions like this.