What is a block?
A block is one counting object. In this lesson, each pictured block counts as one.
Each of the blocks in this group counts as one object.
There are 5 blocks. Each block is one part of the total.
Count each whole block once. Count every block, but do not count the same block twice.
Count one block at a time
Say the counting numbers in order from 1 to 20. Give each block one number. Point to or touch each block once so you do not skip one or count it twice.
Point to the blocks from left to right. The numbers below show the counting order.
Say, “1, 2, 3, 4, 5.” The last number is five, so there are 5 blocks.
Use one number for each block. Keep the numbers in the same order every time you count.
Recognize groups from 0 to 20
A numeral tells how many blocks are in a group. Match the numeral to a group with the same total. These examples show zero and groups of five, ten, fifteen, and twenty.
0
Zero
1
One
2
Two
3
Three
4
Four
5
Five
6
Six
7
Seven
8
Eight
9
Nine
10
Ten
Zero is a number too. It names a group with no cubes.
Count blocks from 6 to 10
After five, continue the number sequence: 6, 7, 8, 9, 10. Arrange blocks in rows and count each row from left to right.
Count five blocks on the top row. Start at the left of the next row and continue counting.
There are 10 blocks. The last number you say is ten.
When you begin another row, start at its left side and continue with the next number. Do not start over at one.
Count blocks from 11 to 15
After ten, keep counting: 11, 12, 13, 14, 15. You can count ten blocks first, then count on for the next five.
Count the two rows of five, then the third row of five.
The numbers continue from eleven through fifteen. There are 15 blocks.
A full row of five helps organize the blocks. Still point to each block once as you count.
Count blocks from 16 to 20
Continue after fifteen: 16, 17, 18, 19, 20. Count each row from left to right, then move to the left side of the next row.
Here are four rows of five blocks. Count each row in order.
The last number is twenty, so the group has 20 blocks.
For a group of twenty, four rows of five make the blocks easier to follow. Count all four rows.
Understand zero blocks
Zero means none. If a group has no blocks, its count is 0.
The group is empty. There are 0 cubes.
An empty group has zero blocks. Count only the blocks that are present.
The last number tells how many
When you count a group carefully, the last number you say tells how many blocks there are altogether. This number is the total.
Count, “1, 2, 3, 4, 5.” The last number is 5, so the total is 5 cubes.
You do not need to start again to tell how many. Remember the last number you said.
The arrangement can change
Blocks can be placed in different arrangements. If no blocks are added or taken away, the total stays the same.
In a row
3 cubes
In a triangle
3 cubes
Count each group. Both groups have 5 blocks, even though their arrangements are different.
Do not guess from the shape of the group. Count the cubes to check.
Match a numeral to the blocks
To match a numeral and a group, read the numeral and count the blocks. They match when the numeral and the total are the same.
The numeral 5 matches the group because there are 5 blocks.
Look at the numeral, count the cubes, and check that the two amounts match.
Check your count
Use this careful routine: look, point, count, and tell. Make sure every cube has been counted exactly once.
- Look: Find all the cubes in the group.
- Point: Point to one cube at a time.
- Count: Say the numbers in order.
- Tell: Say how many cubes there are altogether.
For example: “I counted 1, 2, 3, 4, 5. There are 5 blocks.”
If you lose your place, begin again and point to each cube once. Counting slowly helps you keep track.
Notes for teachers
This resource provides clear explanations, visual examples, and practice for counting blocks from 0 to 20. It may be used for whole-class instruction, guided practice, independent learning, review, homework, or extra support at home.