Grade 1 · Unit 1: Number and place value

Estimating and rounding

A good guess is a clever start.

How many oranges?

The seller has a big pile of oranges. Counting them all would take a long time. We can estimate: make a sensible guess.

See it without counting

Look at this ten frame for a moment. You can see 7 without counting one by one: a full row of 5 and 2 more. Dice dots work the same way.

Estimate, then count

First look and say: about 10? about 20? Then count to check. There are 18. “About 20” was a good estimate.

Rounding to the nearest ten

Where is 27 on the number line? It is closer to 30 than to 20. So 27 rounds to 30. A 5 in the ones place rounds up.

Still the same number

Spread out 5 apples. Are there more now? No! There are still 5. Check your answers: is your answer about right?

What I learnt

• I can estimate how many things there are.
• I can see small numbers without counting.
• I can round numbers to the nearest ten.