Add Multiple Numbers
Give your first grade math whiz a challenge by asking him to add three, four, and five numbers together. He may find the task daunting at first, but there's a trick to add multiple numbers here: find the numbers that add up to ten first, then add the rest together. A classic mental math trick, adding to ten first makes solving complicated addition problems much easier and quicker. For an extra challenge, have him add up all the numbers in his head as fast as he can!