# 1st Grade Computation and Algebraic Thinking Resources

## Arranged Ten Frames

A random number of dots (up to 20) are placed into ten frames. Choose whether the dots are "arranged" or "random". Lots of different, randomly generated possibilities.

## Balance (The Farmer's Stone)

There's a sack on a scale. How much does it weigh? Use the weights to find out and explore flexible approaches to equality.

## Balanced Expressions

Explore notions of equality and inequality by dragging expressions to the balance. Select whether you'd like your inequalities recorded with the "not equal" sign (â‰ ) or greater/less than signs (> and <).

## Commuting Counters

Enter two addends, then click next. The addends will show up as counters. Keep clicking next to see the commutative property in action.

## Dots in the Box

A missing addend activity. There are ___ dots in a box. Some are red and some are blue. If you know how many blue dots there are, can you figure out how many red dots there should be?

## Five by Five

A 2-player, GeoGebra version of Sara VanDerWerf's game. You will place (up to) 25 numbers in the grid. You score by placing (by clicking) matching numbers in adjacent squares. Decide whether you want to play a timed or untimed game, and whether you'd like the scores to be calculated by sums or products. See Sara's blog post for more information.

## Move the Number

This activity is meant to develop flexible, creative thinking about numbers and operations. Your goal is to move a from a starting number to a target number, but there are many ways to do this! Adjust the sliders to control the bounds of the numbers involved.

## Moving Dots

How many dots are there? How do you see it? This number talk resource is designed to give students lots of different ways of seeing and describing a number of dots, but with the added advantage of seeing the dots move from one arrangement to another. Use this with the goal of students flexibly describing many ways of composing/decomposing a number.

## Number Balance

Explore ideas around equality, decomposition, missing addends, and more! Up the ante by finding the mystery number.

## Part-Part-Whole Estimation

Adjust the slider to control the size of the numbers. One of the pieces (a part or the whole) is randomly provided. Use estimation to fill in the rest. Feedback provided.