Grade by Grade
B. Number · Number Sense: Numbers to 200 and Fractions

Reading, Writing and Using Numbers to 200

B1.1About 35 minutes
Learning goals
  • I can read and write numbers to 200 in digits and in words.
  • I can show a number to 200 in different ways.
  • I can tell how numbers are used in everyday life.

Words to know

digit
One of the ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. The number 152 has three digits.
number word
A number written in letters, like one hundred twelve.
represent
To show a number in a way you can see, like with blocks, a drawing or a number line.
three-digit number
A number with three digits, like 100 or 175.

Numbers are everywhere!

Look around your home or your street. You will see numbers on houses, buses, books, clocks and food boxes.

Many of these numbers are bigger than 100. In this lesson you will learn to read them, write them and show them in different ways.

Reading three-digit numbers

A number like 147 has three digits. We read it in two parts:

  1. The first digit tells the hundreds: one hundred
  2. The last two digits are a number you already know: forty-seven

So 147 is one hundred forty-seven.

DigitsWords
100one hundred
105one hundred five
112one hundred twelve
130one hundred thirty
147one hundred forty-seven
168one hundred sixty-eight
199one hundred ninety-nine
200two hundred
Some numbers between 100 and 200, in digits and in words

Spelling helpers

  • forty has no "u" (not fourty).
  • Use a hyphen (little dash) in numbers like twenty-one to ninety-nine: one hundred sixty-two.
  • In math we say "one hundred five", without "and". We save the word "and" for amounts like "2 and a half".

Writing numbers from words

When you hear "one hundred sixty", don't write 100 and then 60 (10060)! That is far too big.

Think: 1 hundred and 6 tens and 0 ones. Write the three digits: 160.

Worked example

Example 1: Number to words

Write 183 in words.

  1. The first digit is 1, so start with one hundred.
  2. The last two digits make 83. In words that is eighty-three.
  3. Put them together.

one hundred eighty-three

Worked example

Example 2: Words to number

Write one hundred nine in digits.

  1. One hundred means a 1 in the hundreds place.
  2. "Nine" has no tens. We need a 0 to hold the tens place.
  3. Nine ones: 9.

109. The 0 is important. Without it, 19 would be a different number!

Showing a number in many ways

Here are some ways to represent the number 125:

1 hundred, 2 tens, 5 ones
With base ten blocks: 1 hundred flat, 2 ten rods and 5 small cubes.
100105110115120125130135140145150
On a number line: 125 is halfway between 120 and 130.
Way to show it125
Digits125
Wordsone hundred twenty-five
Hundreds, tens, ones1 hundred, 2 tens, 5 ones
Adding parts100 + 20 + 5
Quarters5 quarters = 125 cents (25, 50, 75, 100, 125)
Five ways to show the same number

How do we use numbers?

Numbers have different jobs:

  • Counting how many: 150 people in the school gym.
  • Measuring: a desk is 120 centimetres long. The oven is at 180 degrees.
  • Putting things in order: the 100th day of school. Page 112 comes after page 111.
  • Naming or labelling: bus number 105, the house at 132 Maple Street, a hockey jersey with 87. These numbers are names. We don't add them!
Worked example

Example 3: What job does the number have?

"Our class read 142 books this year." What job does 142 have?

  1. Ask: Is it telling how many, how long, what order, or is it a name?
  2. 142 tells how many books.

142 is used for counting how many.

Just for fun

Here's a funny-but-true spelling fact: forty is the only number word in English whose letters are in alphabetical order. F, O, R, T, Y. Maybe that's why it doesn't want a "u"!

Hands-on activity

Number hunt

You need: paper, a pencil, and a grown-up.

  1. Walk around your home (or neighbourhood) and look for numbers bigger than 100. Look at book pages, food boxes, flyers, the oven dial, house numbers and bus signs.
  2. Write down 5 numbers you find.
  3. Read each number out loud to your grown-up.
  4. Write one of them in words.
  5. For each number, say its job: counting, measuring, ordering, or naming.

Math talk: "Which number was the biggest? Which job was most common?"

Your turn

1

Read this number out loud: 156

2

Write one hundred forty in digits.

3

Write 172 in words.

4

Write one hundred three in digits.

5

Show 134 as hundreds, tens and ones.

6

"Turn to page 118." What job does 118 have?

7

Write two hundred in digits.

More practice: warm-up

1

Read out loud: 120

2

Write in digits: one hundred fifty

3

How many digits are in 186?

4

Write in words: 111

5

Write in digits: one hundred one

More practice: on your own

1

Write one hundred ninety-four in digits.

2

Kai wrote "one hundred thirty" as 10030. What should it be? Why?

3

Write 165 in words and as adding parts.

4

Which number is a name, not an amount? a 150 cm ribbon, bus 150, 150 stickers

5

Draw base ten blocks for 116. Tell what you drew.

Challenge

1

I am a number between 100 and 200. In words, I end with "-seven". My tens digit is 8. What number am I?

2

Find two different numbers to 200 that are written with the digits 1, 0 and 5, used once each.

3

Show 140 in two different ways that are not digits or words.

Check your understanding

Quiz

1.

How do we write one hundred sixty-one in digits?

2.

How do we read 108?

3.

Which is spelled correctly?

4.

Which shows 153?

5.

In "Room 112", what job does 112 do?

6.

Which equals 100 + 70 + 9?

For parents and teachers

Big idea: A three-digit number is read as "___ hundred" plus the two-digit number your child already knows. Numbers have different jobs: counting, measuring, ordering and naming.

Common difficulties:

  • Writing numbers the way they sound ("one hundred twenty" written as 10020). Have your child say how many hundreds, tens and ones, then write one digit for each.
  • Forgetting the zero (writing 19 for one hundred nine). Ask: "How many tens are there? We need a digit to say zero tens."
  • Mixing up teens (113 and 130). Say them slowly: one hundred thirteen versus one hundred thirty.
  • Spelling forty and ninety. These don't need to be perfect at this age, but point them out.

A note on "and": Many adults say "one hundred and five". That's fine in conversation. In school math, children learn to say "one hundred five", because later "and" is used for fractions and decimals.

How to help: Read numbers you see on signs, flyers and house numbers. Ask "Is that number counting, measuring, putting in order or naming something?"