New
New
Year 6

Explain how adjusting one part affects the sum

I can explain how adjusting one addend or part affects the sum or whole.

New
New
Year 6

Explain how adjusting one part affects the sum

I can explain how adjusting one addend or part affects the sum or whole.

Lesson details

Key learning points

  1. If I increase this part or by __ then the whole will increase by the same amount.
  2. If I decrease this part by __ then the whole will decrease by the same amount.
  3. A balance beam can represent unequal expressions or inequalities.

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.

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.

Make use of bucket scales and cubes for children who need to enact this concept initially.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is the missing number in this part-whole model?
An image in a quiz
Correct Answer: 630
Q2.
What is the missing number in this part-whole model?
An image in a quiz
Correct Answer: 0.47
Q3.
In digits, write the number being represented by the place value counters.
An image in a quiz
Correct Answer: 7,300, 7300
Q4.
In digits, write the number being represented by the place value counters.
An image in a quiz
Correct Answer: 5.8
Q5.
Which of the following are equations?
100 ÷ 2 + 233
Correct answer: 7 × 3 + 20 = 20 × 2 + 1
3 + 8 × 10
Correct answer: 5 × 10 = 53 − 3
Q6.
What is the unknown in this equation? 4.3 + = 4.1 + 1.5
Correct Answer: 1.3

6 Questions

Q1.
In an addition equation, if one part is adjusted and the other parts remain the same, what happens to the whole?
It stays the same.
Correct answer: It is adjusted by the same amount.
The inverse process is used to undo the adjustment.
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?
Correct answer: Add 400
Subtract 400
Nothing
Q3.
If a part is adjusted by subtracting 4.06, what will need to be done to the whole?
Add 4.06
Correct answer: Subtract 4.06
Nothing
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?
Correct Answer: 107, 107 cards
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?
An image in a quiz
Correct Answer: 22,650, 22650
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
An image in a quiz
Correct Answer: 14.7