Playing Battleship in Math

In kindergarten, we are expanding our number sense and preparing for the upcoming 100th day of school. Number sense is a person's ability to understand, relate and connect numbers. This knowledge of our number system helps people to develop math concepts with a deeper understanding and better fluency. When celebrating the 100th day of school, we need students to be able to do so much more than just count to 100. In order to really enjoy all the games and stations students need to be able to count on from a given number, skip count by 5s and 10s, estimate and compare quantities, and understand place value. One fantastic way to prepare for all of this is working with a hundreds chart. 

Our favorite way to develop our number sense and use a hundreds chart is by playing Battleship. We have modified it a bit in kindergarten, but the concept is basically the same. Each student receives a hundreds chart and ten unifix cubes. They need to first build their four ships with cubes. One four-cube ship, a three-cube ship, a two-cube ship and a one cube ship. They then hide these ships on their hundreds chart. I have them use a crayon to mark around where they placed their ships in case the board accidentally gets bumped. Now that they have set up the fun begins! They take turns guessing a number on the board. Their partner says either hit or miss and they mark their board with a X if they missed the ships or color in the square if they hit a ship. The game continues until someone sinks all the ships. 

The best part of the game is that they do not even realize how much place value, addition and subtraction they need to use when they are trying to find the ships. They first have to pick a number and find it on their chart. Sometimes they need to count by tens and then count on when finding the number on their chart. Also if they have a hit, they have to strategically guess other numbers around the number they hit in order to sink a ship with more than one cube. If they guess 57 and the ship isn't sunk they need to add/subtract one or ten to find the next part of the ship. Once they believe they have sunk the ship they can ask if it is sunk by reading back all the numbers. If it is sunk, the ship is removed from their partners board. We had so much fun playing today that we forgot about all the math skills we were working on!