Unitising means treating groups that contain, or represent, the same number of things as ‘ones’ or ‘units’. It is important in understanding place value and supports us to think multiplicatively.

Count a large group of objects by counting tens and ones

Maths

Explore the counting sequence for counting to 100 and beyond

Count groups of ten and extra ones

Represent a number from 20 to 99

Use a number line to position and estimate the numbers 20-99

In this unit pupils will explore the counting sequence for counting to 100 and beyond and represent the numbers from 20-99 in different ways including marking the position on a number line. They learn to represent 20-99 as a length. In the future unit pupils consolidate their counting across and on from 100. They will learn to represent a three-digit number up to 199 in different ways.

In the prior unit pupils extended their counting to 100 They explored pattern in counting, focused on the end of the decade and the start of the new decade numbers. In this unit pupils will explore the counting sequence for counting to 100 and beyond representing numbers from 20-99 in different ways including marking the position on a number line They will learn to represent 20-99 as a length.

In this unit pupils will explore the counting sequence for counting to 100 and beyond representing numbers from 20-99 in different ways including marking the position on a number line They will learn to represent 20-99 in the context of length.

Counting and representing the numbers 20 to 99

There are 6 groups of ten and 4 more ones.

There are 4 groups of ten and 6 more ones.

Which place value chart matches the one hundred square?

Which of the following represents the same value as the one hundred square?

Which of the following images represents the same value as the one hundred square?

I’m thinking of a number which is on the one hundred square. It has more than 8 tens and it has 2 ones. What is my number?

Which of the following describes the picture?

Laura has put her cubes into groups of ten and has some more ones left over. Which place value chart represents her cubes?

How would you write the number eighty-nine in digits?

There are 4 groups of ten and 5 extra ones.

There are 5 groups of ten and 4 extra ones. 

There are 9 groups of ten and no extra ones.

Andeep has 54 straws. He puts them into groups of ten and there are some more ones left over. Which of the following could describe his group?

Match the numbers that have the same value.

Andeep counts his pencils in ones. He has 37 pencils. If he puts them into groups of ten, how many extra ones will he have left over.

Count a large group of objects by counting tens and ones

Lesson outcome