Explain how adjusting one part affects the sum
Lesson details
Learning outcome
I can explain how adjusting one addend or part affects the sum or whole.
Key learning points
- If I increase this part or by __ then the whole will increase by the same amount.
- If I decrease this part by __ then the whole will decrease by the same amount.
- A balance beam can represent unequal expressions or inequalities.
Keywords
Equation - An equation is used to show that one number, calculation or expression is equal to another.
Adjustment - An adjustment is a change to a number using either subtraction or addition. This can be done to a part or a whole.
Whole - The whole is all the parts or everything, the total amount.
Part - A part is some of the whole.
Common misconception
Many pupils understand the equals symbol as 'makes' or a the symbol you simply place in front of the answer. This can make the idea of a balanced equation tricky, undoing concepts like adjustment.
Get all the pupils to write an expression (as unique as possible) that is equal to 10 and display them in the classroom. Ask the children what symbol could be placed between all of them and explore why.
Teacher tip
Make use of bucket scales and cubes for children who need to enact this concept initially.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the missing number in this part-whole model?
Q2.What is the missing number in this part-whole model?
Q3.In digits, write the number being represented by the place value counters.
Q4.In digits, write the number being represented by the place value counters.
Q5.Which of the following are equations?
Q6.What is the unknown in this equation? 4.3 + = 4.1 + 1.5
Assessment exit quiz
6 Questions
Q1.In an addition equation, if one part is adjusted and the other parts remain the same, what happens to the whole?
Q2.If a part is adjusted by adding 400 and the other parts remain the same, what will need to be done to the whole?
Q3.If a part is adjusted by subtracting 4.06, what will need to be done to the whole?
Q4.Aisha has 36 Battle Robot Cards and Sofia has 56, so between them they have a collection of 92 cards.
Aisha is given 15 more for her birthday. How many do they have between them now?
Q5.The diagram shows Aisha and Sofia’s joint score in a paired arcade game. At the end of the game, Aisha gets a penalty reduction in points of 1,350. What is their joint total now?
Q6.Aisha and Sofia’s pet cats have a combined weight of 15.4kg. After a month, Sofia’s cat loses 0.7kg in mass. Their new combined mass = kg
To help you plan your 6 maths lesson on: Explain how adjusting one part affects the sum, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 6 maths lesson on: Explain how adjusting one part affects the sum, 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 addition calculations unit, dive into the full primary maths curriculum, or learn more about lesson planning.