To represent something means to show something in a different way.

Use a bar model to represent spatial problems with two unknowns

Maths

In this unit pupils will compare and represent the structure of problems with two unknowns using a bar model. They will systematically solve problems with two unknowns using trial and improvement. In the future unit this understanding is formalised through the use of algebraic notation. 

In the prior unit pupils explained how to balance equations with addition or subtraction expressions and used knowledge of balancing equations to solve problems. In this unit pupils will compare and represent the structure of problems with two unknowns using a bar model. They will systematically solve problems with two unknowns using trial and improvement.

Solving problems with two unknowns

Which set of bar models is it best to compare with?

 This pattern is made from two different-sized equilateral triangles. It is not to scale. What is the side-length of the smaller equilateral triangle? {{ }} cm

 This pattern is made from two different-sized equilateral triangles. It is not to scale. What is the side-length of the larger equilateral triangle? {{ }} cm

This pattern is made up of two different-sized squares. Tick the pair of equations that represent the problem.

This pattern is made up of two different-sized squares. What is the length of the shorter sided square? {{ }} cm

This pattern is made up of two different-sized squares. What is the length of the longer sided square? {{ }} cm

What is the value of the gap marked ? in the bar model? Give your answer in pounds. £{{ }}

What is the value of f in the bar model? Give your answer in pounds. £{{ }}

What is the value of d in the bar model? Give your answer in pounds. £{{ }}

Aisha buys 3 croissants and 2 baguettes for €2.80   Sam buys 5 croissants and and 2 baguettes for €4.40
What is the cost of a croissant?

This lesson will soon be taken down.

Use a bar model to represent spatial problems with two unknowns

Lesson outcome