Mental Math with Regrouping Helps

Here are some great resources online for your kids to practice mental math and addition with two-three digit numbers:

http://www.adaptedmind.com/gradelist.php

I would suggest clicking on the "Two-Digit Addition with Carrying" link. They can play a game where they get points as they get more right.

A few more good websites:

http://www.coolmath4kids.com/addition/05-addition-lesson-two-digit-numbers-01.html

And here is a super fun game I'm sure they will LOVE:

http://funschool.kaboose.com/formula-fusion/games/game_addition_attack.html