Addition Facts: 99 + 99 + 99

What?! 99 + 99 + 99 is not in your addition facts? How would you compute that?

Math Addition facts are great to pick up speed on adding numbers. At our Math Learning Center, we love to challenge kids just one step further. The video below showed how our Chief Instructional Officer Larry Martinek makes adding 99 + 99 + 99 make sense to a grown adult. No, it’s not adding them up in vertical columns or adding it up one at a time and memorizing the subtotals. It’s easier than that.

Kids who can see math in their heads see 99 + 99 + 99 as adding 100 three times, than subtracting 1 for each 100 to arrive at the answer: 297. In a snap. All in their head. No paper and pencil. That’s called plain old Number Sense – something we are constantly trying to develop in the children in our Math Tutoring Center.

In the video below, our Chief Instructional Officer, Larry Martinek, illustrates the solution. Watch the video below, then answer the challenge question below the video. No paper or pencil, you’ll see it in your head.

Challenge Question: What’s 7 X 99 ?