Fun Math Game for Kids: Fraction Jack

Looking for a fun way to help your child improve math skills? This card game is a version of Black Jack that’s been reworked to teach math without sacrificing fun!

Materials:

• Deck of cards, divided into two packs:
• One with all red cards (hearts and diamonds)
• One with all black cards (spades and clubs)
• Paper and pencil

Preparation:
No special preparation is needed, but prior to playing, you might want to check in with your child to see what she knows about adding and subtracting fractions with and without common denominators. The following example can give you a little review and be used for checking out your child’s understanding.

Say you are trying to add 2/3 and 4/9. Your denominators are 3 and 9, right? Find the smallest number that both 3 and 9 can be divided into (that number is the “least common denominator”), in this case: 9. 4/9 already has a denominator of 9, so all we have to do is convert 2/3 to a fraction with a denominator of 9 also. Multiply both the numerator and denominator by 3 to get 6/9. Now we can add the fractions easily: 6/9 + 4/9 = 10/9 or 1 1/9.

Goal:
To start, pick a low number – say 5 – to use as your addition target. The goal of this math game is to get as close to that target – either above it or below it – as possible.

Game play:

1. Place your two packs of cards (red and black) face down on the table. In this game, all of the face cards (kings, queens, jacks) are wild and may be given any value from 1 to 10. All the other cards have their actual face value.
2. Go first to show your child what to do. Draw one card from each pack. Form a fraction by using the numerical value of the black card as the numerator and the value of the red card as the denominator. For example, if you draw:
   
   
   
   

   

   Write that fraction down on paper. You will be adding several fractions together.

3. Now you go again, drawing two more cards, forming another fraction and bringing it to lowest terms. This time let’s say you draw:
   
   
   
   

   

   Remember, the jack is wild, so this card can be any number between 1 and 10. We’ll choose 4, making our fraction 3/4.

   Add up the fractions from your two turns. (In our example, 5/4 + 3/4 = 8/4 = 2.) How close is the sum to your target number, 5? Decide whether you should draw again and form another fraction to add. When you decide to “stick” and stop drawing, it’s your child’s turn to draw.

4. Your child goes through the same steps, drawing cards, forming fractions, and then adding fractions together. If she wants to know how close she is to the target 5, you can help her set up the subtraction problem (5 minus the sum of her fractions) to keep track.

   The “hand” is finished when the second player decides she is as close to the target as possible (or when all of the cards are used up). The player who is closest to the target number wins that hand. Then, play Fraction Jack again!

Skills practiced: adding fractions, subtracting fractions, simplifying fractions, reducing fractions, finding the lowest common denominator

What games do you play to help your child practice math?