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Compare the structure of problems with one or two unknowns

Lesson details

Learning outcome

I can compare the structure of problems with one or two unknowns.

Key learning points

  1. Unknowns can be connected additively.
  2. Unknowns can be connected multiplicatively.
  3. Representations can show if unknowns are related additively or multiplicatively.

Keywords

  • Difference - The difference is the result of subtracting one number from another. How much one number differs from another.

Common misconception

Pupils struggle to understand how to represent the number rods to show the difference when trying to find the missing rod.

Ensure pupils spend time representing each question with an equation then match this with the number rods. This may help them to visualise the missing part as well.

Teacher tip

If the pupils have not spent much time yet with number rods, ensure they are allowed time to explore these for themselves.

Licence

This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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Prior knowledge starter quiz

6 Questions

Q1.
Write in the missing number: 30 + = 180

Correct Answer: 150

Q2.
Tick the possible solutions for ___ + ___ = 180

35 and 155
Correct answer: 40 and 140
25 and 160
Correct answer: 20 and 160

Q3.
What is the missing angle? °

An image in a quiz
Correct Answer: 30

Q4.
Without applying commutativity, how many possible solutions are there if each of the missing values are integers? ___ + ___ = 10

5
Correct answer: 6
8
9
10

Q5.
Which pair of numbers that sum to 10 have a difference of 4? ___ + ___ = 10

5 and 5
6 and 4
Correct answer: 7 and 3
8 and 2
9 and 1

Q6.
Write the number that is two-thirds the size of 15

Correct Answer: 10

6 Questions

Q1.
Two rods are equivalent to the dark green rod. One of them is red. What is the missing rod?

An image in a quiz
Red rod (A)
Light green rod (B)
Correct answer: Pink rod (C)
Yellow rod (D)

Q2.
Two rods are equivalent to the dark green rod. One of them is light green. What is the missing rod?

An image in a quiz
Red (A)
Correct answer: Light Green (B)
Pink (C)
Yellow (D)

Q3.
Two rods are equivalent to the yellow rod. What could be the missing rods be?

An image in a quiz
Correct answer: A: Red and light green
B: Pink and red
Correct answer: C: White and pink
D: White and light green

Q4.
Two rods are equivalent to the pink rod. What could be the missing rods be?

An image in a quiz
A: Red and light green
B: White and red
Correct answer: C: White and light green
Correct answer: D: Red and red

Q5.
Two rods are equivalent to the blue rod. There is a difference of red between the rods. What rods could they be?

An image in a quiz
Light green and red
Correct answer: Yellow and light green
Light green and white
Yellow and pink

Q6.
Two rods are equivalent to the dark green. One rod is twice the size of the other rod. What rods could they be?

An image in a quiz
Red and yellow
Red and light green
Light green and white
Correct answer: Pink and red

To help you plan your 6 maths lesson on: Compare the structure of problems with one or two unknowns, download all teaching resources for free and adapt to suit your pupils' needs...