What are odd and even numbers?

Even numbers can be split into two equal groups with no block left over. Odd numbers have one block left over when you try to make pairs.

How can Numberblocks help teach odd and even?

The block shapes make pairs visible. Children can see whether a Numberblock has a partner for every block or one block standing alone.

Which numbers from 1 to 20 are even?

The even numbers from 1 to 20 are 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20.

Which numbers from 1 to 20 are odd?

The odd numbers from 1 to 20 are 1, 3, 5, 7, 9, 11, 13, 15, 17, and 19.

Can I use this activity in class?

Yes. Use the sorter for a quick whole-class demonstration, then ask children to explain why each number belongs in the odd or even group.

Numberblocks Odd and Even - Sort the Numbers

Choose a Numberblock, see whether it makes equal rows, then drag numbers into the odd or even sorting zones.

Odd/Even Sorter

Odd Blocks!

The top row has one extra block, so this Numberblock is odd.

Drag Sorting Game

Drag the number card into Odd or Even, or tap a sort button.

Sorted

0

Correct

0

Accuracy

100%

8 cards left in this round

14Drag me

Drop Odd

Drop Even

Desktop: drag the card. Touch screen: use the sort buttons.

What Are Odd and Even Numberblocks?

Numberblocks odd and even activities help children see number patterns instead of memorizing a rule. Even Numberblocks can be grouped into pairs, while odd Numberblocks always have one block left over.

This page works well after exploring the Numberblocks 1 to 100 chart. Children can also open the Numberblocks Generator to inspect a larger number, or try Numberblocks Square Numbers to compare another math club.

How to Use the Odd and Even Sorter

1

Pick a Number

Type a number or use +1 and -1 to browse Numberblocks.

2

Check the Rows

Even numbers make two equal rows. Odd numbers leave one extra block.

3

Drag to Sort

Drag each random number into the Odd or Even zone.

4

Watch Accuracy

Use the stats panel to track sorted numbers and correct answers.

Odd and Even Numbers 1 to 20

Odd Numberblocks

1, 3, 5, 7, 9, 11, 13, 15, 17, 19

Even Numberblocks

2, 4, 6, 8, 10, 12, 14, 16, 18, 20