INTRODUCTION TO HUNDREDTHS

DAY 14

Extending place value to hundredths

Key Mathematical Ideas

Conceptualise the meaning of 1 on the Linear Abacus® when working with hundredths.
Find ways to model tenths and hundredths on the Linear Abacus®.
Understand how to extend the base 10 place value system to include decimal fractions beyond hundredths.
Counting by tenths and hundredths and understanding the sequence of decimal numbers.

This video can be used for the explicit instruction to help you guide children through the tasks.

The key skills and understandings that are highlighted in the video and which you should encourage children to explore as they work with the abacus strings are:

Seeing the relationship between tenths, hundredths, and thousandths.
Explaining what happens to the base 10 groups as they grow or shrink using the abacus strings to reason and symbols.
Understanding how to count by decimal fractions and explain how to order decimal fractions.

What are the relationships between each of the representations i.e., the tenths and hundredths? Describe what you see using the Linear Abacus®.
What patterns do you notice when counting by hundredths?
How many hundredths make one tenth? How can you see this on the Linear Abacus®?
Which decimal number do you think is larger 0.3 or 0.18? Explain your thinking, then use the abacus string to find out.
What if you wanted to model the next base 10 group can you explain what would come after hundredths? How could this be modelled on the abacus string?
Is there more than one way to do this

Exploration

How can 1 be modelled on the Linear Abacus® so that you can represent hundredths?

Once you have determined this explain what:
1. Each row of colour (10 beads) represents.
2. Each individual bead represents.
Then practice counting by hundredths on the Linear Abacus® from 0 to 0.1. What do you notice when you reach one-tenth.

Share their creative thinking on our Mathematics Community Forum

Support

Encourage children to use the representations modelled on page 82.

Extension

Ask children to represent mixed numbers like 1.25 or 2.08 on the Linear Abacus®. How many strings are required for both numbers? Show how you can find these numbers in the sequence.

Micro Writing Task

Complete day 14 of your journal. For parents and teachers this prompt encourages children to critique their thinking where they learn to analyse their mathematical arguments or solutions. This thinking is enhanced by connecting the resource to the solution.