Number Combination

In math, we have been discussing making the numbers 5,6,7,8,and 9 with two addends. While exploring the different combinations, students are looking for patterns and beginning to build addition fact fluency. The students are really developing strong number sense. For example, some students noticed that only the even numbers have a doubles fact! The students also know the commutative property for addition, that 2+3 is the same as 3+2. In the upcoming weeks, we will be exploring the combinations for 10-20.

Here is a quick classroom video of making five. We are using one of our new technology tools, the MimioMobile app and Mimio Interactive Projector. One of the features of the app allows up to nine ipads to collaborate on the whiteboard. We used the app in this math lesson to show all the different combinations for making five. Each table group had an ipad recorder. The rest of the students at the table did a "shake and spill." To shake and spill, students had five two color counters in a cup. They would shake the cup and spill the counters and then give the combination of red and yellow counters to the ipad recorder. Once the recorder wrote all the combinations spilled at their table, we gathered on the floor to discuss results. Since all the ipads are projected, we had 15 different combinations to discuss. We found that there are six different two addend combinations for five: 5+0, 0+5, 4+1, 1+4, 3+2, and 2+3. Further, through the collaboration, the children also realized that it was more common to shake and spill and 3+2 combination than 5+0. The MimioMobile tool created an opportunity for a rich mathematical discussion.



There are a couple great apps for practicing addition combinations. In Find Sums, students have the opportunity to practice combinations for 4-20 and 100. The practice can be with picture support or just symbolically. Click Find Sums to see the app in the itunes store.

In the game Hungry Fish, students have to feed the fish a certain number. They have to combine bubbles to make the designated number so the fish with eat it. Click Hungry Fish to be linked to the game in the app store.