Calculate the difference using knowledge of an adjusted subtrahend: difference structure
Lesson details
Learning outcome
I can calculate the difference using knowledge of an adjusted subtrahend in a difference structure
Key learning points
- The more you subtract the smaller the difference.
- The less you subtract the greater the difference.
- A number line can be used to represent the change in the subtrahend.
Keywords
Minuend - The minuend is the number being subtracted from.
Subtrahend - A subtrahend is a number subtracted from another.
Difference - The difference is the result after subtracting one number from another.
Adjust - When you adjust you make a change to a number. This is done to make a calculation easier to solve mentally.
Common misconception
Many pupils will try to adjust the difference in the same way that the subtrahend has been adjusted without considering the use of the inverse.
Start simply with double-sided counters to show the concept practically.
Teacher tip
You can get the children to create their own sequences of equations with missing numbers to solve for one another. Give certain parameters to avoid overly complex numbers and make sure they know to alternate between concealing the subtrahend or difference each time.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.If the subtrahend is 262, which part of the bar model below is the difference?
Q2.Solve the following calculation mentally by adjusting the minuend and subtrahend.
285 − 77 =
Q3.Solve the following calculation mentally using unitisation.
= 3,900 − 1,300
Q4.Solve the following calculation mentally by adjusting the minuend and then the difference.
4,008 − 1,300 =
Q5.Solve the following calculation using a mental strategy.
= 703 − 146
Q6.Look at the jottings. What was the value of the adjustment to the subtrahend and the difference?
Assessment exit quiz
6 Questions
Q1.Jun and Laura are flipping coins and recording the results as they go. They each flip the coin 72 times. The table shows how many they each got except one blank cell. How many tails did Laura get?
Q2.Jun and Laura are flipping coins and recording the results as they go. They each flip the coin 150 times. The table shows how many they each got except one blank cell. How many heads did Jun get?
Q3.Jun and Laura each take the same number of shots at the goal ring in netball. Jun scores 20 Laura scores 17 but misses 18 How many did Jun miss? misses
Q4.Jun and Laura each take the same number of shots at the goal ring in netball. Laura misses 32 and scores 21 Jun misses 16 only. How many did Jun score? Jun scored
Q5.Look at the pair of equations and use the complete one to help find the missing number in the second.
Q6.Look at the pair of equations below and use the complete one to help find the missing number in the second.
To help you plan your 6 maths lesson on: Calculate the difference using knowledge of an adjusted subtrahend: difference structure, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 6 maths lesson on: Calculate the difference using knowledge of an adjusted subtrahend: difference structure, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 2 maths lessons from the Use equivalence and compensation to simplify and solve subtraction problems unit, dive into the full primary maths curriculum, or learn more about lesson planning.