Counting to 20

Learning intention

Students will learn how to:

count to 20 using 1–1 correspondence.

Success criteria

I will know I have been successful if I can:

count a collection of up to 20 objects by counting up and check by counting back.

Prerequisites

Counting sequence to 20 forwards and backwards

Language

Reinforce the use of mathematical language: count, count forwards, count backwards

Misconceptions

• All objects in a count must look the same.
• It does not matter if you count objects more than once.

Before the video

• Engage children in the theme of ‘collecting’ by asking what they collect.
• Place a collection crate in the classroom and ask children what collections they could create in the classroom.
• Discuss what makes a collection and how we know how many objects are in each collection.

During the video

First viewing:

Watch the video without stopping or pausing. Then, ask the children to explain what happened in the video. Begin to draw out key vocabulary or possible misconceptions. 

Second viewing:

Pause the video at the following stages to create class instructions on how to count collections successfully.

Pause point	Key learning	Action/discussion
0:54	Number line	Ask children how the objects have been labelled. What does it remind them of? Compare to the classroom number line resources they are familiar with.
1:18	Checking counting by counting backwards	How did he check his counting? How was it different to how the stones were first counted? Highlight that he counted backwards.
2:11	Organising collections to count	Ask children why he has asked for the erasers to be in single file. Explore what this means and how it makes counting easier.
2:50	Need to check counting	What mistake was made? Discuss the impact of counting an object twice.

After the video

Class collection crate:

• Students select collections from the class collection crate and lay the objects out in single file.
• Students lay out Mathletics number cards to create a number line and count the objects in the collection.
• Students check the number of objects by counting backwards and returning the objects in the collection to the collection crate.

‘My collection crate’ checklist task:

• Students create their own collection crate using objects in the classroom.
• Students use the ‘My collection crate’ worksheet to make a checklist for the collections in their crate.
• Students can swap their checklist with a partner to check their counting.

Download resource

Mathletics worksheet:

Download worksheet

Counting strategies:

• Display car counting shot from the video (3:52).
• Explore how else the cars could be counted (eg in twos).
• Select the Mathletics number cards to make a ‘counting in twos’ number line.
• Instruct students to practise counting collections in twos.