Addition 2: Landing On Solid Ground

Now that we've learned how to add 2 units together, now let's try adding 2 tens together. We start with the one column and work our way to the final colomn. Let's say we have 17, and we add 6. We start at the one colomn, 7 + 6. What is 7+6? If 6+6 is 12, then 7+6 must be 13! Here comes the tricky part. Because the number is bigger than 9, we need to carry the 1 over to the tens colomn. Now, what was the unit (one) in the answer? If you said 3, you are correct! So we put 3 in the ones colomn. Now for the tens colomn. You may be temped to say, "well, one plus nothing = 1, so I should put a one there," WRONG!! Don't forget get about that one we carried. If one + nothing = one, then what should we do with the carried number (1)? We add it to the sum of the tens (the answer in the tens colomn)! So now we have 1 + 1. What is the answer? 2!! So the sum (total) is 23!! If you guessed that, Hurray!! If not, read the lesson again or go to www.khanacademy.org and do their exercices.