Numbers to at least 120 | Year 1

01 / LEARN

Understand the method.

THE CORE RULE

109 + 1 = 110

Count one more. After 109 comes 110.

Keep going after a nine

After twenty-nine comes thirty. The same pattern continues: after ninety-nine comes one hundred.

Now count the extra ones: 101, 102, 103. After 109 comes 110, then 111, 112 and so on.

108, 109, 110, 111

Say it, then write it

116 says one hundred and sixteen. Keep the digits in that order.

Point to each number as you count. Say one number for each step so that you do not skip a number.

02 / WORKED EXAMPLES

See the method in action.

EXAMPLE 01

Crossing a ten

What number comes just after 109?

Worked solution

1
Count one more.
$109 + 1 = 110$
The nine extra ones become another ten.
2
Say the number.
$110$
One hundred and ten comes just after one hundred and nine.

Answer

110

EXAMPLE 02

Read a short count

Read 117, 118, 119 and 120 aloud.

Worked solution

1
Read the first three numbers.
$117, 118, 119$
One hundred and seventeen; one hundred and eighteen; one hundred and nineteen.
2
Keep counting to the next ten.
$120$
The next number is one hundred and twenty.

Answer

One hundred and seventeen; one hundred and eighteen; one hundred and nineteen; one hundred and twenty.

03 / YOUR TURN

Try it yourself.

Calculate, explain, then apply.

CHECK 01

Your turn

What comes just after 119?

Show answer & reasoning

120

Counting one more takes 119 to 120.

Keep practising

6 worksheet questions

Open worksheet Worked solutions

Read the questions online

Write the number after 99.
Write the missing number: $103, 104,__, 106$ .
Write one hundred and twelve in digits.
Say 108 in words.
Write the next three numbers after 117.
Write the missing numbers: $119,__, 121,__, 123$ .

Read the worked solutions

Write the number after 99.
Count one more: $99, 100$ .
100
Write the missing number: $103, 104,__, 106$ .
Count one more at each step.
105
Write one hundred and twelve in digits.
One hundred plus twelve is written 112.
112
Say 108 in words.
There are no extra tens.
One hundred and eight.
Write the next three numbers after 117.
Add one each time.
$118, 119, 120$
Write the missing numbers: $119,__, 121,__, 123$ .
Count onwards without skipping a number.
$120, 122$

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Curriculum reference & lesson scope

Australian Curriculum v9 and SA Curriculum Mathematics

Year 1 counting, place value and partitioning.

Official curriculum source ↗

In this lesson

Understand the method.

Keep going after a nine

Say it, then write it

See the method in action.

Crossing a ten

Count one more.

Say the number.

Read a short count

Read the first three numbers.

Keep counting to the next ten.

Try it yourself.

Your turn

Keep practising