# Sums Investigation

This task comes from a book in a series of three books by Math Solutions, called Math for All: Differentiating Instruction. This is another investigation where students can practice addition and think about combinatorics – a nice way of organizing counting. The task ends with asking students to write about their thinking.

#### Task Instruction

Getting Started- Write the numbers 12, 15, 19, and 24 on blank cards.
- Put your number cards in a bag and shake it.

- Pull out two cards. Record the numbers and their sum.
- Return the cards to the bag and take another turn.
- Do this a few times.

- How many different sums do you get when you pull two of these number cards from the bag?
- How do you know you have all the possibilities?

- Write about your thinking.

#### Reference

*From Math for All: Differentiating Instruction, Grades K-2 by Linda Dacey & Rebeka Eston Salemi (Sausalito, CA: Math Solutions), pp. 210. Reprinted with permission.*