B. Number · Number Sense: Numbers to 1000 and Fractions

Reading, Writing and Using Numbers to 1000

B1.1 A1About 35 minutes

Learning goals

I can read numbers to 1000 out loud.
I can write numbers to 1000 in numerals and in words.
I can explain how numbers are used in everyday life: to count, to measure, to name and to put things in order.

Words to know

numeral
A number written with digits, like 472.

digit
One of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9.

number word
A number written with letters, like four hundred seventy-two.

hyphen
A short line (-) that joins two words, like seventy-two.

label
A number used as a name, like a house number or a jersey number.

Remember from Grade 2

In Grade 2 you read and wrote numbers up to 200. Now you will read and write numbers all the way to 1000. The good news: if you can read 200, you already know most of what you need!

Numbers are everywhere

On Saturday, Maya saw lots of numbers:

Her house number is 245.
Her library book has 312 pages.
She is 132 cm tall.
She came 3rd in a race at the park.

Today you will learn to read and write numbers like these, and think about how each number is being used.

Reading three-digit numbers

To read a three-digit number, say the hundreds first, then say the rest of the number the way you already know.

245: "two hundred forty-five"
312: "three hundred twelve"
507: "five hundred seven" (0 tens, so we say nothing for the tens)
860: "eight hundred sixty" (0 ones, so we say nothing for the ones)
1000: "one thousand"

Read the hundreds digit first, then read the last two digits as a number you already know. In 507 the tens digit is 0, so nothing is said for the tens.

Ones	Teens	Tens
one, two, three	ten, eleven, twelve	twenty, thirty
four, five, six	thirteen, fourteen, fifteen	forty, fifty, sixty
seven, eight, nine	sixteen, seventeen, eighteen, nineteen	seventy, eighty, ninety

Number words you need to write any number up to 999. Then add one thousand!

Spelling tips

Forty has no u (four, but forty).
Put a hyphen between a tens word and a ones word: twenty-one, forty-five, ninety-nine.
In math class we say "four hundred twelve", without the word "and".

Worked example

Example 1: Numerals to words

Write 476 in words.

The 4 is in the hundreds place: four hundred.
The rest is 76: seventy-six. Remember the hyphen.
Put it together.

four hundred seventy-six

Worked example

Example 2: Words to numerals

Write six hundred three as a numeral.

Six hundred means 6 in the hundreds place.
There are no tens, so write 0 in the tens place.
Three means 3 in the ones place.

603. Not 6003 and not 63. Every three-digit number needs a digit in each place.

Number words	Hundreds	Tens	Ones	Numeral
six hundred three	6	0	3	603
nine hundred fifteen	9	1	5	915
four hundred eighty	4	8	0	480

A place-value chart helps you write numerals with zeros in the right place.

How do we use numbers?

Numbers have different jobs. Here are four big ones:

Counting (how many?): 312 pages, 24 students in a class.
Measuring (how much? how long? how heavy?): 132 cm tall, 500 grams of flour, $8.
Naming (labels): house number 245, bus route 15, the number on a hockey jersey. These numbers are names. We don't add them or count with them.
Ordering (which place?): 1st, 2nd, 3rd in a race, page 52 in a book, the 1st of July (Canada Day).

Maya's numbers doing four different jobs: counting pages, measuring height, labelling a house, and ordering places in a race.

Worked example

Example 3: What job does the number do?

Sort these: (a) the 7 on Ava's hockey jersey, (b) 7 cookies on a plate, (c) 7 kg of potatoes, (d) Ava came 7th in line.

(a) The jersey number names Ava on the team. It is a label.
(b) We count the cookies. It tells how many.
(c) Kilograms tell how heavy. It is a measurement.
(d) 7th tells her place in line. It shows order.

(a) label, (b) counting, (c) measuring, (d) ordering

Math talk

When you explain your thinking, use words like "I know ___ because ___." For example: "I know 507 is five hundred seven because there are 5 hundreds, 0 tens and 7 ones." Talking about math helps you remember it.

Just for fun

Here is a sneaky fact: write every number from one to nine hundred ninety-nine in words, and you will never use the letter a. The first number with an "a" is one thousand!

Hands-on activity

Number hunt

You need: paper and a pencil. Ask a grown-up before you take anything out of a cupboard.

Look around your home for 10 numbers. Try a cereal box, a calendar, a clock, a recipe, a book, a flyer or a remote control.
Write each number as a numeral. If it is 1000 or less, also write it in words.
Beside each number, write its job: counting, measuring, label or ordering.
Which job did you find the most?

Math talk: "Why can't we add two house numbers to get something useful?"

Your turn

Write 382 in words.

Write 704 in words.

Write 990 in words.

Write as a numeral: five hundred sixty-one

Write as a numeral: eight hundred eight

Write as a numeral: one thousand

"Our house number is 417." What job does the number do?

More practice: warm-up

Write 215 in words.

Write as a numeral: four hundred

Write 999 in words.

Which is spelled correctly: fourty or forty?

How many digits does 1000 have?

More practice: on your own

Ella wrote "two hundred seven" as 2007. What should she write? Why?

Write 650 in words. Why don't you say a ones word?

Write 119 in words.

"The bread costs $4." Is the number used to count, measure, label or order?

"Our class went to Room 214." What job does 214 do? How do you know?

Challenge

Use the digits 3, 0 and 8 once each to make every three-digit number you can. Write each one in numerals and words. (A number can't start with 0.)

Write the number that is one more than nine hundred ninety-nine as a numeral and in words.

Think of a number from your own life for each job: counting, measuring, label and ordering.

Check your understanding

Quiz

How do you write four hundred twelve?

How do you write 760 in words?

Which number is a label?

Which word is spelled correctly?

Which numeral is nine hundred nine?

Which number tells order?

For parents and teachers

Big idea: Children should read and write numbers to 1000 and understand that numbers are used in different ways. The curriculum (B1.1) asks Grade 3 students to describe how numbers are used in everyday life.

Common difficulties:

Writing what they hear: "six hundred three" becomes 6003 or 63. Use a hundreds-tens-ones chart so every place gets a digit, including 0.
Reading zeros: 507 read as "fifty-seven". Ask: "How many hundreds? How many tens?"
Spelling: forty, ninety and the hyphen in numbers like seventy-two.
Labels: children may think every number tells "how many". House numbers, phone numbers and jersey numbers are names.

How to help: Read numbers aloud together on signs, flyers and receipts. Ask "What is this number's job?" Have your child write cheques or price tags for pretend shopping in words. Saying "I know ___ because ___" builds the habit of explaining thinking (Strand A).