Grade by Grade
B. Number · Number Sense: Numbers to 50 and Fractions

Comparing and Ordering Numbers to 50

B1.3About 30 minutes
Learning goals
  • I can tell which of two numbers is greater or less.
  • I can tell when two amounts are equal.
  • I can put numbers in order from least to greatest and from greatest to least.

Words to know

greater than
More. 30 is greater than 20.
less than
Not as many. 12 is less than 15. We say fewer when we can count the things: fewer apples.
equal
The same amount. 5 and 5 are equal.
least
The smallest number in a group of numbers.
greatest
The biggest number in a group of numbers.
order
To put numbers in a line from smallest to biggest, or from biggest to smallest.

Who has more?

Noah collected 28 maple leaves. Zoe collected 32 maple leaves. Who collected more?

In this lesson you will learn how to compare numbers (find out which is more or less) and how to order numbers (put them in a line from smallest to biggest).

Comparing by matching

When we have objects, we can line them up and match them one to one. The row that has some left over has more.

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Match each banana with an apple. 2 apples have no partner. So 7 is greater than 5, and 5 is less than 7.

Comparing with tens and ones

For bigger numbers, matching takes too long. Instead, compare the tens first!

  1. Look at the tens. The number with more tens is greater.
  2. If the tens are the same, look at the ones. The number with more ones is greater.
  3. If the tens and ones are both the same, the numbers are equal.
Worked example

Who collected more leaves?

Noah has 28 leaves. Zoe has 32 leaves. Who has more?

  1. Look at the tens. 28 has 2 tens. 32 has 3 tens.
  2. 3 tens is more than 2 tens.
  3. So 32 is greater, even though 8 ones is more than 2 ones! The tens matter most.

Zoe has more. 32 is greater than 28. And 28 is less than 32.

Noah: 28 leaves (2 tens and 8 ones).
Zoe: 32 leaves (3 tens and 2 ones). Zoe has one more full ten!
Worked example

Same tens

Which is greater: 45 or 41?

  1. Look at the tens. Both have 4 tens. They're the same, so look at the ones.
  2. 45 has 5 ones. 41 has 1 one.
  3. 5 ones is more than 1 one.

45 is greater than 41.

Comparing on a number line

On a number line, numbers get bigger as you move right and smaller as you move left. The number that is farther to the right is greater.

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17 is left of 26, so 17 is less than 26. 39 is the farthest right, so it is the greatest.

Math symbols

You might see these signs in older kids' books:

  • > means greater than. 9 > 4
  • < means less than. 4 < 9
  • = means equal to. 5 = 5

The open mouth always faces the bigger number! In Grade 1, saying the words is what matters most.

Ordering numbers

To order numbers, we put them in a line.

  • Least to greatest means smallest first, biggest last (going up, like climbing stairs).
  • Greatest to least means biggest first, smallest last (going down).
Worked example

Put them in order

Put these numbers in order from least to greatest: 25, 9, 41, 17

  1. Find the least number first. 9 has no tens at all, so it is the least.
  2. Next look at the numbers with tens: 17 has 1 ten, 25 has 2 tens, 41 has 4 tens.
  3. Fewer tens comes first: 17, then 25, then 41.

9, 17, 25, 41

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On the number line, the numbers go from left to right: 9, 17, 25, 41.
Worked example

Between numbers

What numbers are between 36 and 40?

  1. Count up from 36: 36, 37, 38, 39, 40.
  2. Between means the numbers in the middle. We don't include 36 or 40.

37, 38 and 39 are between 36 and 40.

Worked example

One more and one less

What number is one more than 29? What number is one less than 29? What number is ten more than 29?

  1. One more means count forward 1: 29, 30.
  2. One less means count back 1: 29, 28.
  3. Ten more means one more ten: 2 tens and 9 ones becomes 3 tens and 9 ones, 39.

One more is 30, one less is 28, and ten more is 39.

Just for fun

Some people imagine the > and < signs as a hungry crocodile. Its open mouth always wants to gobble the bigger number. Chomp!

Hands-on activity

Number card war

You need: paper cut into 20 small cards and a pencil (or a deck of cards with the face cards removed).

  1. Write the numbers from 1 to 50 on cards (pick any 20 numbers).
  2. Mix them up and split them between two players, face down.
  3. Both players flip one card. Read your numbers out loud.
  4. The player with the greater number says "\_\_ is greater than \_\_" and takes both cards.
  5. If the numbers are equal, flip again!
  6. Play another round where the least number wins.

Bonus: flip 4 cards and race to put them in order from least to greatest.

Your turn!

1

Which is greater: 19 or 31?

2

Which is less: 44 or 48?

3

Are 3 tens and 5 ones and the number 35 equal?

4

Order from least to greatest: 30, 13, 3, 23

5

Order from greatest to least: 12, 50, 27, 8

6

What number is one more than 39?

7

What number is one less than 20?

8

Name a number between 22 and 26.

More practice: warm-up

1

Which is greater: 14 or 41?

2

Match the apples and pears. Which row has more?

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3

What number is one more than 44?

4

True or false: 30 is less than 13.

5

Order from least to greatest: 21, 12, 15

More practice: on your own

1

Which is greater: 37 or 33? How do you know?

2

What number is ten more than 26?

3

Order from greatest to least: 18, 40, 9, 35

4

Jacob has 2 tens and 4 ones of hockey cards. Priya has 24 hockey cards. Who has more?

5

Name all the numbers between 45 and 50.

Challenge

1

Find the mistake! Lucas says 29 is greater than 31 because 9 is bigger than 1. Is he right? Explain.

2

I am a number between 30 and 40. I have 5 ones. What number am I?

3

Use the digits 2 and 4 one time each to make a two-digit number. What is the greatest number you can make? What is the least?

Check your understanding

Quiz

1.

Which number is greater than 27?

2.

Which list is in order from least to greatest?

3.

Ali has 42 stickers. Mia has 24 stickers. Which is true?

4.

What number comes between 46 and 48?

5.

On a number line, which number is farthest to the right: 33, 30 or 38?

6.

Which number is less than 18?

7.

What number is one less than 40?

For parents and teachers

What your child is learning: to compare two numbers (greater than, less than, equal to) and to order several numbers up to 50. The key strategy is to compare the tens first, then the ones.

Common mistakes and how to help:

  • Looking only at the ones digit, for example thinking 28 is greater than 32 because 8 is more than 2. Build both numbers with ten frames or bundles so your child sees the extra ten.
  • Mixing up the words "least" and "greatest". Use stairs: least to greatest goes up the stairs.
  • Comparing the size of objects instead of the number. Five big watermelons are not "more" than seven small grapes when we count. Ask "how many?" rather than "how big?".
  • Using the < and > signs. These are not required in Grade 1. If your child uses them, check that they can also say the words.

Everyday practice: compare prices at the grocery store, scores in a hockey game, or how many days until a birthday. Ask "How many more?"

Math talk questions: "How do you know that number is greater?" "Where would that number go on the number line?"