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Counting to 100

Here is a 100 square.

You can use it to count from 1 to 100.

Counting up

Let's use the 100 square to help us count.

If it's useful, you can trace your finger along each square as you count up.

• Can you count from 27 to 35?

• Can you count from 62 to 76?

Counting back

You can use the 100 square to count back, as well as count up.

• Can you count back from 44 to 38?

Now look at how the numbers are arranged.

• Which number is between 34 and 36?

• Which number is between 55 and 75?

Example 1

Use the 100 square to find the mistake in this sequence.

47, 48, 49, 50, 51, 61, 53, 54, 55

Starting from 47 and counting along the rows you get to 52, not 61.

So 61 is not in the correct sequence.

Example 2

Now let's use the 100 square to find numbers 10 more or 10 less.

Which number is 10 more than 26?

Find 26 on the 100 square and count 10 more .What do you notice?

26 + 10 = 36

Now find the numbers 40, 51and 76 and count on 10 more.

What do you notice each time? Can you see a pattern?

Did you notice that 10 more is always beneath the number you started with?

Top tip

Counting up in tens doesn’t change the last digit (ones).

For example:

23, 33, 43, 53, 63, 73, 83

Activity 1

Practise counting up and down in tens by counting up and down the rows.

Trace your finger along the column with the following numbers.

• 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

• 7, 17, 27, 37, 47, 57, 67, 77, 87, 97

• 95, 85, 75, 65, 55, 45, 35, 25, 15, 5

Remember

To count up in ones, count on along the rows of the 100 square.

To count up in tens, count down the columns of the 100 square.

Activity 2

Now try counting the objects in this quiz.

You can use the number square in activity 1 to help you count.