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Don’t Break the Bank!

How to Play

Everyone makes a diagram like this on their paper:

DBTB Setup

Whole Class Game: The teacher (or a student) rolls the die. Whatever number it lands on, everyone enters it in one of the nine spots on the board. After nine turns, the board becomes an addition problem with three 3-digit numbers to add together. The goal is to get the highest sum without going over 1000. (See next page for example game.) Small Group Game: Same as whole class game, except that you take turns rolling the die, and everyone ends up entering different numbers into their grid.

Why We Love It

Don’t Break the Bank is a Place Value powerhouse. It takes very little time, so it can be used as a warmup or in those five minutes before class ends. It’s fun, and kids love it, even though it involves addition practice. And, while kids will usually break the bank (that is, go over 1000) their first few games, they’ll inevitably start estimating and choosing good strategies for themselves. Should the digits in the hundreds column add up to 9 or 8? How common is it to carry? The deeper thinking is almost inevitable.

Variations

Don’t Break the Bank is easy to adapt to other situations. Want to do it for subtraction? Multiplication? You just need to decide on a board that involves some choice, and a “bank” to avoid breaking. Don’t be too worried if you misjudge what the bank should be–picking the right bank can be an interesting discussion to have with your class.

DBTB Example

About this Lesson

2 comments

Lesson Notes

CCSS.Math.Content.2.NBT.A.1 CCSS.Math.Content.2.NBT.A.3 CCSS.Math.Content.2.NBT.A.4 CCSS.Math.Content.2.NBT.B.5 CCSS.Math.Content.2.NBT.B.6 CCSS.Math.Content.2.NBT.B.7 CCSS.Math.Content.3.NBT.A.2 CCSS.Math.Content.4.NBT.B.4

Comments 2

  1. Jenny Hough

    This is cool! I really appreciate that you can adapt this one easily for other situations. One thing, on my computer, I didn’t see any diagram for the first part.

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