Doubles and Doubles Plus and Minus One, Lets Have Some Fun!

During our Math Workshop times, we have been learning lots of new math strategies while learning our doubles facts.  Learning our doubles facts helps us solve problems quickly.  If we know that 7+ 7 = 14, then 14-7=7.  When solving 7+8, we can use the doubles plus one strategy.  If we know that 7+7=14, then 7+8=7+7+1, which equals 15.  We could also use the doubles minus one strategy to solve this problem.  If we know that 8+8=16, then 7+8=8+8-1, which equals 15! Knowing our doubles facts and using the doubles plus and minus one strategies makes solving problems much easier!  Here's a picture of some of the games I made to help us learn our doubles facts and to help us practice our doubles plus and minus one strategies while making our Math Workshop times so much fun!

Here are some of our favorite Doubles Games!

Here's some games that help us practice the Doubles Plus and Minus One Strategies while having fun!

Here we are during our Math Workshop times and W.I.N. times playing games while learning our 

Doubles facts and using the Double Plus and Minus One strategies while having some fun!

During our unit on Addition and Subtraction to 20, we also learned the Make a 10 strategy to help us solve problems quickly.  For example, when solving 8+5 we can break the 5 into a 2 and a 3, and add the 2 to the 8 to make a 10.  By taking the 2 from the 5 and adding it to the 8, we have made 8+5 equal to 10+3, which equals 13.  We have been using cubes to build problems and quickly regroup to make a ten, which makes problems much easier to solve.  When children become more comfortable using this strategy, they start to automatically look at equations in a different way.  When solving 9+6 they quickly see that they can mentally make a 10 and 9+6 becomes 10+5, which equals 15!

You can have your child show you how we use this strategy and practice this strategy at home by having your child use pennies instead of cubes, just remind them to build the problems by making a ten frame so they can see how to make a ten quickly. Some of the children may even be ready to use mental math strategies to automatically make a ten.  

You can even use a deck of cards to play a fun card game to reinforce the doubles plus and minus one and make a ten strategies! Simply take out the Jacks, Queens and Kings in a deck of cards and place the rest of the cards in a pile between you and your child.  Have your child flip over 2 cards and find the sum as quickly as possible.  If your child gets an 8 and a 6 for example, instead of watching them count on from the 8, encourage them to make a 10 by taking 2 from the 6 and adding it to the 8 to make a 10.  Now 8+6 becomes 10+4, which equals 14.  

If your child isn't ready to do this using mental math strategies, then they can use pennies, buttons or any other small counters to help them work the problem out.  Again, just remind them to build the problems by making a ten frame.  You can play a game with a child similar to "war", where each person take turns flipping over two cards, finding the sum as quickly as possible using our new strategies.  The person with the greatest sum wins that round and takes all 4 cards!