All skills Math

Learn Index · Number Sense and Numeration Grade 1–2

Comparing and ordering numbers

Deciding which numbers are bigger or smaller and putting them in order.

Read

Bigger or smaller?

To compare numbers means to decide which is bigger, which is smaller, or whether they are the same. To order numbers means to put a whole list in a line from least to greatest (smallest to biggest), or from greatest to least.

You do this all the time: Who scored more points? Which toy costs less? Who is the oldest in your family?

Comparing with a number line

On a number line, numbers to the right are bigger.

0 — 5 — 10 — 15 — 20 — 25

So 21 is bigger than 14, because it is further right.

Comparing with place value

For two-digit numbers, look at the tens digit first:

Number Tens Ones
14 1 4
21 2 1

21 has 2 tens; 14 has only 1 ten. So 21 is bigger, even though 4 is bigger than 1 in the ones digit.

Rule: compare the biggest place first. Only look at the ones if the tens are the same.

Compare Tens the same? Decide by Bigger
36 and 52 No Tens: 5 > 3 52
47 and 43 Yes (4) Ones: 7 > 3 47
9 and 12 9 has no tens Tens 12

A one-digit number is always smaller than a two-digit number.

Ordering a list

  1. Find the least number and write it first.
  2. Find the next smallest and write it next.
  3. Keep going until you reach the greatest.
  4. Check: does every number get bigger as you read along?

Worked examples

Example 1: Order from least to greatest: 14, 9, 21.

9 has no tens, so it is least. 14 has 1 ten, 21 has 2 tens. Answer: 9, 14, 21.

Example 2: Order from greatest to least: 58, 85, 55.

Tens: 8 > 5, so 85 is greatest. 58 and 55 both have 5 tens; ones: 8 > 5. Answer: 85, 58, 55.

Example 3: Which is smaller, 70 or 69?

Tens: 6 < 7, so 69 is smaller.

Common mistakes

  • Reading only the ones digit. 19 is not bigger than 31 just because 9 > 1.
  • Mixing up the direction. "Least to greatest" starts small; "greatest to least" starts big.
  • Forgetting a number when rewriting a list. Cross each one off as you use it.

Try it yourself

  1. Which is greater: 38 or 83?
  2. Order from least to greatest: 27, 72, 7.
  3. Order from greatest to least: 40, 44, 14.
  4. Which is the least: 61, 16, 66?

Answers: 1) 83 2) 7, 27, 72 3) 44, 40, 14 4) 16

Quick recap

  • Compare the tens digit first, then the ones digit.
  • Numbers further right on a number line are bigger.
  • Order from least to greatest or the other way, then check.