Clumsy Thief: The Game That Teaches How To Add In Your Head

Clumsy Thief is a cartoony, wildly addictive addition game for kids ages 7-11.

I’ll be straight up with you: Clumsy Thief can get loud. You may also have to deal with weeks of kids begging, “PLEASE can we play Clumsy Thief? Pleeeeeaaaase??”

Which, you know, there are worse things than your kid begging to play a math game.

But I can pretty much guarantee you that your kid will come away with some awesome new math skills she didn’t have before.


Clumsy Thief has three versions, each with a different math goal. The rules of play are the same in each.

CLUMSY THIEF: In the original game kids find pairs of numbers that add to 100. They’ll get good at recognizing pairs of numbers like 80+20, 55+45, and 25+75 as combos that add to 100.

CLUMSY THIEF IN THE CANDY SHOP: In Candy Shop, kids find pairs of numbers that add to 20. They’ll get good at finding pairs of numbers like 13+7, 4+16, and 18+2.

(NEW) CLUMSY THIEF JUNIOR: Kids find number pairs that add to 10.


AGES: 7-11 years


BEST FOR: mental addition

  1. Deal 7 cards to each player.
  2. Look at the numbers in your hand and try to find pairs that add to 100. Put these pairs in separate piles, face up on the table with only the top card showing.
  3. Look around at the piles in front of the other players.
  4. You can play on their piles if you have a number that pairs to make 100. For example, if you see a 15 at the top of a pile, you can play your 85 on top of it.
  5. Steal any pile you play on and add it to your own. (Yeah, this is the best part!)
  6. The stealing continues, all at the same time, until no-one else can play.
  7. Players draw cards until someone can play, and it all begins again.

There are a few special card that add strategy and make things even more exciting. A thief can be played on any pile to steal it. It can only be stolen again by another thief, or by a jail card.

A jail card can only be played on a thief–and those cards are yours forever.

When all the cards are played, count up the value of your cards in piles of 100. The one with the most money wins.


There are a couple of issues that tend to come up when I see kids playing Clumsy Thief. Here’s how I deal with them.

  1. A child hasn’t learned the number pairs yet, so misses chances to play. The first time we play, we look through the cards and think of number pairs that add to 100. Kids can check this sheet as we play until they feel more confident.
  2. It’s hard to hold all those cards. Sometimes I have them make two rows of cards–finished pairs out front, and their own cards spread out on the ground behind them. This also means I can look at her cards and help out if I see something she’s missed.
  3. Getting upset when someone steals her cards. All you can do is good-naturedly remind them that this is a stealing game…and if she watches closely, she’ll be able to steal it back!


The good: It’s unreal how quickly kids learn to add large numbers in this game. And it’s a card game–takes up next to no storage space.

The bad: Kids can get a little obsessive about it. I sometimes have to forcibly remove it from their line of sight so they will do something else once in awhile.

The verdict: A no brainer–best birthday present ever, and it teaches math, too! Absolutely snatch this one up if you’re looking for a great addition game for kids.

>> Buy Clumsy Thief on Amazon.

This post contains affiliate links. 

Kelli Pearson
Author: Kelli Pearson

Kelli Pearson at Artful Math brings creative math experiences to kids who are underwhelmed by worksheets and tired of feeling like they’re bad at math. With a playful spirit and down-to-earth BFF vibe, she helps kids tap into their powerful brilliant selves and learn math with joy.

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