Step 4 Objective

Compare and order a mixed set of numbers or measurements with up to three decimal places.

Examples of what pupils should know and be able to do

Put these in order, largest/smallest first:

5.25, 15.3, 5.78, 5.87, 5.2

7.765, 7.675, 6.765, 7.756, 6.776

Probing questions

What do you look for first when you are ordering numbers with decimals?

Which part of each number do you look at to help you?

Which numbers are the hardest to put in order? Why?

Give me a number between 3.12 and 3.17. Which of the two numbers is it closer to? How do you know?

What do you do when numbers have the same digit in the same place?

What if pupils find this a barrier?

Encourage pupils to look at the value of the digit on the left.

Pupils may find it helps to read the numbers in words including the place value, e.g. reading 6.25 as 6 units, 2 tenths and 5 hundredths, which is smaller than 6.3 (6 units and 3 tenths).

Practise with situations that pupils are comfortable with, e.g. metres or money. Extend from two decimal places to three decimal places.

Write numbers on cards so that they can sort them, move them around, compare and discuss.