# Kindergarten Number Sense 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.

## Comparing and Estimating Whole Numbers

Use the given quantity to estimate the others. Use the sliders to adjust the size of the numbers (10 to 1000) and number of questions. Kindergartners might use this to talk about more/less, while 6th graders might have highly sophisticated approaches involving unit rate.

## Comparing Small Numbers

A random amount of circles or squares is drawn in each box. Which box has more in it? Count the number in each to help you decide or to justify your answer.

## Comparing Two Whole Numbers

Intended for students to develop understanding of bigger/smaller numbers. Type in two whole numbers. Click "Forward" to see the numbers shown in base-10 blocks, then broken apart into ones, then finally shown overlapping. An interesting example is comparing 3 to 30.

## How Many?

A random number of objects (between 0 and the upper limit you specify) flashes on the screen. Estimate how many you saw. Then display the picture again, reconsider your guess, and finally see the answer. Designed to develop solid connection between a number and how "big" it actually is.

## How Many? (with grouping)

An updated version of "How Many?" with a new feature: once you see the squares, you can arrange them into groups. Use this to connect estimation and quantity to skip counting. Or use it to have a conversation about multiplication or division.

## Interactive Number Grid

This grid goes to 120. Click on the numbers to toggle the colors. Click on an arrow to turn the entire row or column red. Explore 1 or 10 more/less, patterns in skip counting or beyond.

## Making 10's

Specify an number, then watch as it goes from a collection of "ones" to groups of "tens." See the various forms of a number to build understanding of place value. Alternatively, specify a number, make it into tens, then break the tens into ones to develop understanding of regrouping. See also "Showing Numbers with Place Value"

## Making Numbers with Place Value

Enter any number of hundreds, tens, and ones to see that number drawn in any of three ways. One way of using this is to help students see the difference between a digit and its value. For example, a student might say the number 63 has 60 tens and 3 ones. If you enter that in this applet, you can see a number represented as...

• 60 tens and 3 ones ("How I typed it")

• 6 hundreds and 3 ones ("Standard place value")

• 603 ones ("All ones")

## 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.

## Number in Four Forms

See numbers 0 - 20 expressed in ten frames, base 10 blocks, number line, and numerals. Intended to help students see the significance of a group of ten across representations. "How does this show us a group of ten? How does it show us the ones place?"

## Number Path

An exploration of +/- 1 or 10 on the hundreds chart. Make a "path" (of up to 50 squares). Your job is to figure out the numbers. By clicking on the square, the number is revealed.

## Place Value Bars

Enter a whole number (under 1 million) and it will be shown as a bar partitioned along base-10 values. Use this for a visual demonstration of, for example, why 543 > 345, beyond "because 5 is bigger than 3".

## Placing Numbers (up to 30 or up to 50)

An unmarked number line is provided, with 0 on the left. Students are given a random number (either 1-10 or 11-30/50) to place on the number line (repeated up to 20 times). The goal is not only to place numbers in the right order, but also in the correct relative position (e.g. 2, 3, 8, but the 3 should be closer to the 2 than the 8). Feedback is provided by displaying the correct locations based upon the location of the largest number.

## Racing Bears

A set of three related applets (addition, subtraction, and both) taken from the game "Racing Bears" in Math Fact Fluency by Jennifer Bay-Williams and Gina Kling. This version was designed for students who are learning remotely and intended to be used along with GeoGebra Classroom (the "Create Class" button at the top right of the page) to allow teachers to monitor students' work. The small checkbox at the right of the applet displays how many right and wrong moves the students has made.

## Rekenrek

A simple tool to develop understanding of numbers and relationships. Use this for number talks and many other activities.

## Showing numbers

Intended for students to get a sense for "bigness" of numbers. Type in a number to see it displayed in an array. If you wish, enter another number to see a visual comparison.

## Ten Frames

One or more ten frames appears on the screen (you can adjust this). A randomly generated number of dots flashed, (partially) filling in the ten frame(s). Your job is to say how many dots you saw and how you saw it.