Methods of Subtraction

#TheCompleteSeries5lessons

With lesson plans, detailed slides which demonstrate each method, activity ideas, differentiated worksheets and more, this Year 4 'Methods of Subtraction' scheme of work takes away the need for you to do any planning at all...we have it all sorted for you!

#Lesson1EqualsAddition

The first lesson in this series teaches your class how to use the equals addition method to solve subtraction problems. They will find out how to add the same value to both numbers in a calculation, rounding one or the other up to a multiple of ten or a hundred to make the calculation easier to solve. The main activity gives them plenty of opportunities to practise this for themselves and the alternative activity has a 'Sometimes, always or never?' investigation for them to solve!

#Lesson2TheDecompositionMethod

This lesson teaches your class how to use the decomposition method to solve subtraction problems as a pre-cursor to formal column subtraction. They will learn how to partition (or 'decompose') the numbers, aligning them vertically and subtracting each partitioned pair. The slides use Dienes blocks to start introducing the idea of exchanging. The main activity has a fun colour-by-number activity for the children to complete and the alternative activity has some challenging subtraction mazes for the children to work their way through!

#Lesson3LinkingMethods

This lesson will help your class to transition from the informal decomposition method to formal column subtraction, checking in on the expanded method along the way!

They will start by comparing the decomposition and expanded method, noticing that it is the same process in a different layout. They will then have a look at the formal column subtraction method, noting that this is very similar to the expanded method. They will then be challenged to solve subtraction methods using any one of the three methods they have looked at. There is also the opportunity for them to 'be the teacher' as they mark some calculations that have been solved using the three methods to see if their eagle eyes can spot any mistakes!

#Lesson4FormalColumnSubtraction

This lesson focuses on the formal column subtraction method, recapping how the method works and challenging children to start subtracting four- and even five-digit numbers (if they are feeling brave enough!). The main activity will have them competing with a friend to solve calculations with the highest answers to score points whilst the alternative activity will have them sorting calculations into the correct section of a Carroll diagram, depending on their answer.

#Lesson5UsingSubtraction

The final lesson in this series brings together everything the children have learnt about subtraction to help them solve a variety of word problems. The slides go through some one- and two-step problems as a class, encouraging children think about which method would be most appropriate to solve the problem. There are then some questions to answer independently, or some challenging investigations to solve!

Free Overview (Medium-Term Plan)

Download a free overview to support your teaching of this scheme of work.

Free Assessment Grid

Download a free, editable assessment grid to support your teaching of this scheme of work.

Curriculum Objectives covered

• Year 4 - add and subtract numbers with up to 4 digits using the formal written methods of columnar addition and subtraction where appropriate
• Year 4 - solve addition and subtraction two-step problems in contexts, deciding which operations and methods to use and why