Primary 1 maths · Whole numbers · About 8 minutes
Count and represent numbers to 100
Watch the same counters move into groups of ten.
Start the interactive lesson →Practise: Firefly forest
What you will learn
- Count and represent numbers to 100
Models used: number sentences, stories, diagrams.
Let’s make groups of ten
Here are some counters. Let’s put them into groups so they are easier to count.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Here are some counters. Let’s put them into groups so they are easier to count.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Watch these ten counters move together. Ten ones make one ten. The other counters are still waiting.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Here come ten more. Now we have two tens. Ten, twenty.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
We can make one more ten. Ten, twenty, thirty. There are two counters left over.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
Three tens make thirty. Add the two ones: thirty-one, thirty-two. We have thirty-two counters altogether.
30 + 2 = 32
Each small counter is one. Each outlined group holds ten of those same counters. Moving them does not change how many we have.
What did the picture help us see?
Three tens make thirty. Add the two ones: thirty-one, thirty-two. We have thirty-two counters altogether.
Worked example: A new example, together
What is the value in the ones column of 55?
The number at the top of each column is the value of one counter in that column.
Watch the same counters move into groups of ten.
A digit counts units of its place value.
The number at the top of each column is the value of one counter in that column.
Locate the ones column.
A digit tells us how many units there are. Its position tells us what size those units are; that is why a zero can matter.
What is the value in the ones column of 55?
5
The number at the top of each column is the value of one counter in that column.
The digit is 5.
A digit tells us how many units there are. Its position tells us what size those units are; that is why a zero can matter.
The number at the top of each column is the value of one counter in that column.
5 × 1 = 5.
A digit tells us how many units there are. Its position tells us what size those units are; that is why a zero can matter.
The number at the top of each column is the value of one counter in that column.
Check the result against the question we started with.
Adding the place values rebuilds 55.
We found 5. A digit counts units of its place value.
Common mistakes to discuss
- Counting the marks, not the groups. One ten-rod stands for ten ones. A picture of 2 rods and 6 singles shows 26, not 8 objects.
Check your understanding
- Count and represent numbers to 100
- count in tens and ones
- check the answer against the original quantities and units
Explain your reasoning to an adult, then try a fresh question in the interactive lesson. A result from one attempt is not proof of lasting mastery.
Try this lesson →Related Primary 1 lessons
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