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Numbers to 100

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visibility 23update 4 days agobookmarkshare

In this topic you will

Say, read, and write numbers from 0 to 100
Know the value of each digit in a 2-digit number
Count on and back in steps of 1 and 10 from any number

Key Words

column
digit
place holder
representation
row

Show Definitions

column: A vertical line of boxes or numbers in a table or grid.
digit: Any one of the number symbols 0 to 9 that we use to write numbers.
place holder: A symbol used to hold a place in a number, like 0 showing there are no tens or no ones.
representation: A way to show an idea or a number using pictures, objects, words, or symbols.
row: A horizontal line of boxes or numbers in a table or grid.

Patterns in the 100 Square

There are many patterns to discover in the numbers to $100$. You will find out how many tens and how many ones there are in each number to help you to understand the order of the numbers.

EXERCISES

1. Write the missing numbers.

Three place-value partition diagrams showing missing numbers for tens and ones (including 26 split into 20 and 6, and two more similar rows with blanks)

👀 Show answer

In each row, split the number into tens and ones.

Row $1$:$26 = 20 + 6$, so the missing number is $2$ (to make $20$) and $6$ for the ones.

Row $2$:$58 = 50 + 8$, so the missing numbers are $5$ and $8$.

Row $3$:$84 = 80 + 4$, so the missing numbers are $8$ and $4$.

Worked example

This is a row from the $100$ square.

A row of boxes from 21 to 30 with some numbers shown and some missing

Write the missing numbers.

Answer:

Answer:$21,\ 22,\ 23,\ 24,\ 25,\ 26,\ 27,\ 28,\ 29,\ 30$

Answer row showing 21 to 30 in order in green boxes

Count on in ones: $21,\ 22,\ 23,\ 24,\ 25$, then keep counting: $25,\ 26,\ 27,\ 28,\ 29,\ 30$.

The ones change each time you count, and the tens stay the same. From $21$ to $29$ there are always $2$ tens, until you reach $30$.

EXERCISES

$2$. Write the missing numbers.

Three rows of number boxes showing sequences with missing numbers (row from 31 to 40 with 31, 35, 40 shown; row from 61 to 70 with 61, 62, 65 shown; row from 91 to 100 with 95 and 100 shown)

👀 Show answer

Top row:$31,\ 32,\ 33,\ 34,\ 35,\ 36,\ 37,\ 38,\ 39,\ 40$

Middle row:$61,\ 62,\ 63,\ 64,\ 65,\ 66,\ 67,\ 68,\ 69,\ 70$

Bottom row:$91,\ 92,\ 93,\ 94,\ 95,\ 96,\ 97,\ 98,\ 99,\ 100$

Worked example

This is a column from the $100$ square.

Write the missing numbers.

A column from the 100 square showing 2, 12, and 92 with missing numbers in between

Count on in tens: $2,\ 12,\ 22,\ 32,\ 42,\ 52,\ 62,\ 72,\ 82,\ 92$. The tens change when I count. The number of ones stays the same.

Answer:

Answer column listing 2, 12, 22, 32, 42, 52, 62, 72, 82, 92

Answer:$2,\ 12,\ 22,\ 32,\ 42,\ 52,\ 62,\ 72,\ 82,\ 92$

EXERCISES

$3$. Write the missing numbers.

Three vertical number columns with missing numbers (column starting at 5 ending at 55, column starting at 7 ending at 57, and column starting at 10 ending at 100)

👀 Show answer

Orange column:$5,\ 15,\ 25,\ 35,\ 45,\ 55$

Green column:$7,\ 17,\ 27,\ 37,\ 47,\ 57$

Blue column:$10,\ 20,\ 30,\ 40,\ 50,\ 60,\ 70,\ 80,\ 90,\ 100$

Think like a Mathematician

Let’s investigate

A 100 square number grid from 1 to 100

Follow-up Questions:

1. How is every row in the $100$ square the same?

2. How is every row different?

3. Write down what you notice.

👀 show answer

1: Every row has $10$ numbers, and the numbers go up by $1$ each time as you move across the row.
2: Each new row starts $10$ more than the row above, so all the numbers in the next row are $10$ bigger.
3: When you move right you add $1$. When you move down you add $10$. The ones digits repeat in the same columns.

EXERCISES

$4$. Which $2$-digit numbers are represented below?

Three place value pictures: a uses ten-frames with counters, b uses tens rods and ones cubes, c uses ten coins and one coin

👀 Show answer

a.$32$

b.$47$

c.$71$

EXERCISES

$5$. Draw a different representation of the number shown.

Part-whole diagram showing 53 split into 50 and 3, with a large blank box for drawing

Compare your representation with your partner’s.

How are they the same? How are they different?

👀 Show answer

One different representation is to show $53$ as $5$ tens and $3$ ones.

Example:$53 = 10 + 10 + 10 + 10 + 10 + 3$.

Or you can write the expanded form: $53 = 50 + 3$.

Two drawings are the same if they still show $5$ tens and $3$ ones. They are different if they use a different way to show the tens and ones (for example, coins, blocks, or a number line).

EXERCISES

$6$. Here are some pieces of a $100$ square. Write the missing numbers.

Several pieces from a 100 square with some numbers given (including 4, 8, 32, 67, 45, and 79) and blank squares to fill

👀 Show answer

Orange piece:$4,\ 14,\ 24,\ 25$

Purple piece:$8,\ 9,\ 10,\ 19$

Green piece:$32,\ 42,\ 52,\ 53,\ 54,\ 55,\ 45,\ 35$

Blue L-piece (with $67$):$56,\ 57,\ 67,\ 77$

Pink cross (centre $45$):$35,\ 44,\ 45,\ 46,\ 55$

Blue cross (centre $79$):$69,\ 78,\ 79,\ 80,\ 89$

What we've learned

We can say, read and write numbers from $0$ to $100$.
We can explain the value of each digit in a $2$-digit number using tens and ones (for example, $53 = 50 + 3$).
We can count on and back in steps of $1$ and $10$ from any number, using the $100$ square for support.
We can use patterns in the $100$ square: moving right adds $1$, and moving down adds $10$.

Numbers to 100

In this topic you will

Key Words

Patterns in the 100 Square

EXERCISES

EXERCISES

EXERCISES

Think like a Mathematician

EXERCISES

EXERCISES

EXERCISES

What we've learned

Related Past Papers

Related Tutorials

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