# Comparing, ordering, sequencing and estimating

This resource has been developed in partnership with the NSW Mathematics Strategy Professional Learning team, Curriculum Early Years and Primary Learners, and Literacy and Numeracy.

## Using the resource

This resource is the fifth section of a six-part resource supporting number knowledge. Use this resource in conjunction with the other resources in this series in order to support a connected network of critical mathematical concepts, skills and understanding.

## Comparing

From early on, children visually compare quantities to determine which has more or less items. This can be seen when they protest that there has been an unfair share at snack time - “they have more than me!”. This visual comparison works well when the quantities being compared are either very small so we can subitise them or when they are distinctly very different amounts. In this task, when students turn over a domino that is beyond their subitising range or not distinctly different in quantity, then students may use their knowledge of the order of numbers to determine which has less or more.

Teams flip over dominoes and compare the quantities

• Variation 1: Record the difference, the student with the largest (or smallest) difference at the end of 5 (or another chosen number) of rounds is the winner.

• Variation 2: Vary the domino number range

## Estimating

Providing multiple, meaningful experiences in estimating will help students develop increasingly reasonable estimating skills. It is important that estimates are not judged as ‘right’ or ‘wrong’ instead, teachers should support students to talk about estimates as being reasonable or something they would like to revise now that they have considered other evidence.

When estimating measures, teachers can help students identify various attributes that can be used to measure, using both language and gesture.

Students watch the ‘About how many paper clips? videos then practice and discuss estimation techniques.

Students watch the ‘About how many rectangles? videos then practice and discuss estimation techniques.

## Number word sequences

The need to understand forward and backward number word sequences continues to be important beyond the early years of schooling. Due to the complexity of English, special attention is needed to support students in recognising where the patterns in the counting words ‘re-start’ as they cross the decades and the centuries. This is where counting in tens and renaming alongside reciting the number words can support student understanding.

Students learn to estimate large quantities in a container (using dry beans or similar)

• Variation 1: Use the collection to practise counting forwards and backwards by 10, on and off the decade.

• Variation 2: Once the beans have been organised, ‘race’ the students to work out the total with the students counting in the most efficient way and the teacher counting by ones. Use this to discuss why we count in multiples

• Variation 3: Have students represent the amount of beans in other efficient ways such as making an array or grouping 10 tens into 1 hundred.