We all know that our students all learn differently, what works for one student may not be what is going to work for the student sitting next to them. By equipping your students with a variety of ways to solve subtraction problems, you are setting them up for success!
One main factor in the teaching of different subtraction strategies is that students get into the habit of verbally explaining how they got their answer. By continually asking students to verbalise their maths thinking you will avoid the inevitable response of…
“I just worked it out in my head!”
Here’s a resource that will prove helpful time and time again during your maths lessons. This set of 16 sentence starters for maths talks is the perfect way to encourage students to talk about word problems and how they solved them.
How to Teach Subtraction Strategies Successfully
Are you wondering how the teaching of subtraction strategies might look in your classroom? Here is just one method that I used in my classroom successfully.
It’s important to note that the maths rotation activities, completed after the whole group instruction, may look slightly different for each of the subtraction strategies. Some strategies require more consistent prior knowledge and practise to ensure students have the best chance at understanding the concept.
You also might find that your students nail one strategy straight away, however, need further support on another – be guided by your own students.
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(1) Run a Guided Mini-lesson
- Create an anchor chart together with your students, instantly giving them ownership. Alternatively, you can use our Subtraction Strategy classroom posters to help with this explicit instruction.
- Model working through a number of sample problems and sharing your thinking aloud.
- It’s important that you model how to explain how you got to your answer each and every time.
(2) Peer Learning
- This is where your students will have a go at using this particular strategy.
- Keep your students in the same location as the guided mini-lesson and provide them with mini-whiteboards to complete their working out.
- Provide students with a few problems and allow them to pick a problem they feel comfortable working through. This, again, will make them feel at ease.
- I would also get students to work in partners as well so that the less confident students have a safety net.
- Walk around and gauge those students really struggling and those that have totally got it!
- After you’ve given them a suitable time to work out the problem, ask for volunteers to explain how they got their answer – this peer modelling is an important aspect as well.
Sometimes kids just get kids. Peer learning and peer modelling is an important factor!
(3) Maths Rotations
- Set up a variety of hands-on activities and games that relate to the subtraction strategy.
- Students rotate through these activities in their maths groups.
- This is where you can spend some further time with your lower ability students re-explain the concept. This is the perfect opportunity to reiterate and spend time with them ina smaller group environment.
Subtraction Strategies With Activities and Games
It’s important to gauge your students’ prior knowledge of the subtraction strategies to help determine what you plan and organise for your maths rotation activities.
This part of the blog aims to provide an outline of the main subtraction strategies as well as methods to further consolidate the concept of subtraction. Included throughout the blog are some super helpful printable subtraction resources and subtraction games and activities to get you well on your way.
Set your students up for success so they are fist-pumping in no time!
(1) Jump Strategy – Using a Number Line or Number Chart
This is a very popular and visual way to help students work out subtraction problems.
Students use a number line to record the jumps they make and where they land on the line until they get to the answer. This can be done in 10s, 5s, 1s – anything that makes logical sense.
Our Jump Strategy Subtraction Game is a fun and challenging game to use when consolidating the jump strategy on a number line.
Another activity idea is to print one of our many printable number line resources.
You can provide each student with a number line that they can keep close by. Laminate it and get them to use a whiteboard marker to show how they would ‘jump’ along the line to work out a variety of subtraction problems.
An alternative to the number line concept is to use a number chart.
Print out Numbers 1-120 Number Chart, laminate it and have students use whiteboard markers, again and again, to work out a variety of subtraction problems.
When using a hundred chart, students jump up to take 10 and sideways to take 1.
(2) Split Strategy / Partitioning
I have grouped these two strategies together because essentially the concept is similar. It’s about splitting or partitioning the numbers into more manageable parts. This is useful for large numbers.
One way of working out subtraction problems is to split the second smaller number up into place value values. This way works with all types of subtraction sums including those that need regrouping.
For example, the sum 164-48 =.
Students could break the second number into 40 and 8.
Counting back in 10s from 164 to 124 and then subtracting 8 to make 116.
Our Split Strategy Subtraction Dominoes is the perfect small group activity to consolidate the split strategy. The problems have been carefully selected to suit students in the early years. Encourage them to write out their working together as a group for each of the problems.
In partitioning, students expand the numbers into their places before subtracting and then add the parts together. It’s important to note that with this strategy it will only work with subtraction sums that do not need any regrouping of numbers.
So, basically they break the number into place value figures like this:
Example sum: 24-13=
(20-10) + (4-3)=
(10) + (1) = 11
Our Subtraction Bingo game can be utilised at any time during the teaching of different subtraction strategies.
Have students focus on using split strategy or partitioning strategy when required. Or open it up to using whatever strategy works best for them.
(3) Draw a Picture!
Drawing a simple picture (diagram) is also another strategy students could utlise, especially in the early years. Some students are very visual and being able to represent the numbers as items is hugely beneficial to them.
Provide students with a subtraction word problem and get them to use drawing as a strategy to work out the problem. You may like to download our Maths Word Problem Cards for this activity. Provide your students with sticky notes and each student in the group uses a drawing to show their workings.
Have students talk about the different ways each student represented the subtraction problem.
This is where you can talk about the importance of making drawings or diagrams basic. If they are going to spend time drawing 25 students with a lot of detail this could take a lot of time and isn’t beneficial to the end result.
(4) Fact Families – Part-Part-Whole
Having an understanding of the inverse relationship between addition and subtraction through the use of fact families is also another way students in the early years can cement their understanding of subtraction.
When students are exposed to fact families, it can help them memorise basic addition and subtraction facts. Which in turn, can help your students with more complex subtraction problems.
Get your students moving with our fun Moving Mathematics Activity – Fact Family Triangles.
For more active learning game ideas, check out our Active Learning Resource Pack.
(5) Use Known Facts – Mental Maths
In this subtraction strategy, students use mental strategies to work it out in their head by using their knowledge of basic subtraction facts.
Encouraging your students to have instant recall of basic subtraction facts will help them in the long run when working out subtraction problems with larger numbers.
We have a collection of number facts board games to use in your maths rotations. Here are our subtraction specific games:
Our Number Pattern Robot hands-on activity can easily be adapted to focus on very basic subtraction facts.
Pull out the subtraction rule cards and have students practise taking single-digit numbers from two-digit numbers.
(6) Subtraction Algorithm
Some would say the old-school way, the algorithm strategy is still important to teach your students.
Teaching the concept of using an algorithm with no need to regroup is your absolute starting point. Throwing borrowing into the mix straight away can confuse your students.
We do love this poem about subtraction that can make a cute classroom display to help students understand what action to take when working through the subtraction algorithm process:
The Subtraction Poem
More on top? No need to stop!
More on the floor? Go next door!
Digits the same? Zero’s the game!
What about regrouping?
It’s such a tricky concept for the littlies to understand. However, when they are ready and you are game, lot’s of hands-on materials and lot’s of modelling is required.
Here’s one fantastic hands-on activity idea…
Provide students with our 2-digit place value mat, materials that can be broken up such as LEGO blocks or paddle pop sticks and a collection of subtraction problems that need re-grouping.
In this activity, students will start with making the larger number with the materials. They’ll soon notice that when looking at the ones/units number they don’t have enough blocks to take away in the ‘ones’ column. This is where you model the ‘borrowing’ of a block of ten from the tens column.
This visual hands-on representation is a great way for students to get their head around how it works.
That’s a wrap…
Remember, when your children have the tools and understanding – they can all be little mathematicians! No two classes are going to be the same and each student will respond differently to a variety of mathematical concepts and activities. Be guided by your class.
Ingrain into their brains from the start that verbalising how they got to their answer is pivotal to jumping along their own mathematical journey.