One of my favorite activities for composing and decomposing numbers is Shake and Spill, due in large part to how flexibly it can be used.
We often use it to help students practice the combinations for the numbers up to ten, which is a critical Kindergarten skill. But when students are ready for a little more of a challenge, they can also learn that numbers can be decomposed into more than two addends.
But the beauty of Shake and Spill is that it can be used with any number of counters. For example, the target number can be 25. I’m often asked what composing and decomposing numbers looks like with larger numbers. Well, it looks pretty much the same as it does with smaller numbers, except we don’t usually write all the combinations because there are too many. So when students shake and spill 25 counters 5 times, and they get 12 + 13, 18 + 7, 8 + 17, 10 + 15, and 16 + 9, they are experiencing that the number 25 can be composed and decomposed in many ways. Often, when we get to 2- and 3-digit numbers, we only decompose by tens and ones. So kiddos think that 25 can only be 20 + 5. But when they start regrouping to subtract, for example, it’s important that they understand that 25 is also 10 + 15.
The recording sheet for this one is more open-ended. There’s a place to write in the target number and a big, blank space to record the combinations. Here are some suggestions:
- For smaller numbers, have students write each combination as they get it and then make tally marks each time they get the same combination again. You could do this with larger numbers, but it’s not as likely that you’d get the same combination multiple times.
- Have students record their combinations in a t-chart or table. The column headings could be On the Jar and Off the Jar.
- Students can draw a representation for smaller numbers.
- With larger numbers, students can write the equations for the combinations they spill.
- Have students write the fact family for each combination they spill.
I hope you enjoy this holiday freebie! Click here to grab yours. I hope you’ll comment and share it with others. 🙂