Grade by Grade
Strand A: Foundations of Language and Mathematics · Numbers and Counting

Good Guesses: Estimating and Checking

A6.7 A6.10 A5About 20 minutes
Learning goals
  • I can make a thinking guess (an estimate) about how many.
  • I can check my estimate by counting.
  • I can use groups I know, like 5 and 10, to help me estimate.
  • I can tell if my estimate was close, too many, or too few.

Words to know

estimate
A thinking guess about how many, made without counting every one.
about
Close to, but maybe not exactly. "About 10" could be 9 or 11.
check
Count carefully to find the real number.
close
Not far away. 9 is close to 10. 2 is far from 10.

How many grapes?

Grown-up: read aloud. Let your child look at the grapes for a few seconds only, then cover them.

Don't count yet! Just look. Are there a few grapes, or a lot? Make a guess. How many do you think?

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Look, guess, then count to check: there are 8 grapes.

A thinking guess

An estimate is a thinking guess. We look carefully and ask ourselves:

  • Is it a few or a lot?
  • Is it more than 5? Is it more than 10?

Then we say our estimate. After that, we check by counting.

A good estimate is close to the real number. It does not have to be exactly right!

A big white bowl is piled high with green grapes on a kitchen counter.
Are there a few grapes or a lot? Make a thinking guess. Is it more than 10? AI-generated image

Use a group you know

You already know what 5 looks like: one row in a ten frame, or one whole hand. You know what 10 looks like: a full ten frame, or two hands.

Use them to help you estimate. Look at the top row below. It has 5. The bottom row looks about two times as long. So it is about 10.

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Top: 5 strawberries. Bottom: about two rows of 5, so about 10. Count to check: there are 11. That's close!
Worked example

Let's estimate the pretzels

How many pretzels? Make an estimate first.

  1. Look: is it more than 5? Yes, it is longer than one row of 5.
  2. Is it more than 10? Hmm, it looks about the same as 10, maybe a little less.
  3. Say the estimate: "About 10."
  4. Now check. Touch and count: 1, 2, 3, 4, 5, 6, 7, 8, 9.
  5. 9 is just one less than 10. That was a close estimate!

Estimate: about 10. Real count: 9. Close!

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9 pretzels.
Worked example

Which estimate was closest?

Three friends estimated how many acorns were in a cup. Mia said 3. Leo said 20. Ava said 12. Then they counted: 13 acorns.

  1. Mia said 3. That is much fewer than 13. Too few.
  2. Leo said 20. That is more than 13. Too many.
  3. Ava said 12. That is just one less than 13. Very close!
  4. Look at the number line: 12 sits right beside 13.

Ava's estimate (12) was closest to the real count of 13.

01234567891011121314151617181920
The estimates 3, 12 and 20, and the real count, 13. 12 is right next to 13.

Every estimate is welcome

Estimates are thinking guesses, so they are never "wrong". Instead we say: "That was close", "That was too many", or "That was too few".

You can also change your estimate when you learn something new. If you count the first row and find 5, you might change your estimate.

Just for fun

Funny but true: a big watermelon can have hundreds of seeds inside. 🍉 That’s way too many to count at snack time, so it’s a perfect time to estimate!

Hands-on activity

The estimation jar

You need: a clear jar or plastic container, and things to fill it (dry pasta, pompoms, toy cars, apples, mittens).

  1. The grown-up secretly puts 5 to 20 things in the jar.
  2. Everyone looks and says an estimate. The grown-up can write the estimates down.
  3. Pour them out. Count them into rows of 5 or into ten frames.
  4. Whose estimate was closest? Was yours too many or too few?
  5. Next time, fill the same jar with bigger things (like apples). Will more or fewer fit?

Also try: estimate how many giant steps it takes to cross a room, or how many jumps to reach the door. Then do it and count!

Math talk: "Why did you pick that number?"

Your turn

1

Look quickly. Are there more than 5 or fewer than 5 fish? Then count to check.

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2

Which is the best estimate for the stars: 2, 10, or 50?

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3

Liam estimated 10 marbles. He counted 9. Was his estimate close?

4

Estimate how many giant steps from your bed to the door. Then step and count.

5

Grab one handful of cereal. Estimate how many. Then count.

6

Two bowls are the same size. One is full of grapes. One is full of apples. Which bowl has more things in it?

More practice: warm-up

1

A few or a lot?

🐞🐞

2

More than 5 or fewer than 5?

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3

You estimated 4. You counted 4. Was your estimate close?

4

Which is closer to 10: 9 or 2?

5

How do we check an estimate?

More practice: on your own

1

Best estimate for the snowflakes: 4, 15, or 40?

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2

Zoe estimated 20 leaves. She counted 8. Was her estimate too many or too few?

3

Raj estimated 5 blocks. He counted 12. Too many or too few?

4

A row of 5 blocks is on the table. Next to it is a longer row, about two times as long. Estimate the long row.

5

Estimate how many jumps to get across the room. Then jump and count.

Challenge

1

Estimates: 6, 15 and 19. The real count was 16. Which estimate was closest?

2

You count the first row of pinecones: 5. There are 3 rows that look the same. Estimate how many pinecones in all.

3

Two jars are the same size. One is full of beach balls. One is full of marbles. Which jar has more things? Why?

Check your understanding

Quiz

1.

An estimate is …

2.

Which is the best estimate?

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3.

The real count was 7. Whose estimate was closest?

4.

How do we check an estimate?

For parents and teachers

Big idea: Estimating means making a reasonable guess about how many, then checking. The Kindergarten Curriculum (2026) expects children to estimate quantities and check by counting. Good estimates come from number sense: knowing what 5, 10 and 20 look like, and that small objects take up less space.

Common difficulties:

  • Wild guesses ("a hundred!"). That's normal at first. Ask, "Is it more than 5? More than 10?" to help them think.
  • Wanting to count before guessing. Show the group for only a few seconds, or cover it, so they must estimate.
  • Being upset when not exact. Praise close estimates and the thinking behind them. Say "close", "too many" or "too few", not "wrong".

How to help: Keep a weekly estimation jar with different things inside. Estimate in daily life: "How many grapes on your plate? How many steps to the car?" Always check together by counting, and talk about how close you were. Asking "Why did you pick that number?" builds reasoning and communication.