Show a number in parts
326 can be represented as 300 + 20 + 6.
Partitioning helps us see the value clearly.
Year 3
Identify, represent and estimate numbers using different representations
Represent and estimate numbers using place value and number lines.
Lesson overview
Number - number and place value
A number can be shown in different ways, such as digits, words, partitioned values and a position on a number line. Estimating means making a sensible guess by looking at where the number fits.
Estimate on a number line
A point near the middle of 400 and 500 could be about 450.
Think about where the point sits between the marked numbers.
Read different representations
Seven hundred and two is written as 702.
seven hundred and two
The same number can look different in words and digits.
Worked example
Estimate the number marked halfway between 600 and 700.
- Look at the two end points on the number line.
- Halfway between 600 and 700 is 50 more than 600.
- 600 + 50 = 650.
- So the estimate is 650.
Try it
Use the representation to decide what the number must be or where it sits.
Question 1
Which partition matches 541?
Question 2
Which number is halfway between 200 and 300?
Question 3
Which numeral matches 'nine hundred and six'?
nine hundred and six
Question 4
Estimate the middle number between 700 and 800.
Question 5
Which representation shows 480?
Common mistakes
Watch for these when working through the lesson.
- Guessing without using the marks on the number line.
- Ignoring one place-value part when partitioning.
- Mixing up the word form and numeral form.
Related topics
These ideas fit closely with this lesson.
- Read and write numbers up to 1000 in numerals and in words.
- Compare and order numbers up to 1000.