Our teacher diary follows one maths teacher's journey using LbQ. Duncan Whittaker at St Christopherâ€™s Church of England High School gives us a snapshot of its application and its impact in these regular updates.
### ![alt text](/filestore/BlogImage/f8ec82cb-3c55-4469-ac7b-bfa70edd8a55/58a17718-a6a3-4bb9-948a-c5ede219badfDuncanPicEdit.png "Duncan")
Class 7.4: this class are well-behaved and passionate about improving their maths skills. They are at their happiest when using LbQ and the tablets. They are a confident group of students who are unafraid of asking for help when they need it, whether that be from each other or from me. Their average current estimated grade for the end of year 11 is grade 4.
## 17th January 2019
Aim of the lesson: to further explore converting sentences into algebraic expressions using Write Variable Expressions and Equations.
Length of session: 21:41
Number of students: 25
Number of answers: 670
Answers right first time: 68%
## Learning by Questions lesson overview
The previous lesson was a traditional lesson on converting sentences into algebraic expressions. At the start of this lesson, we discussed the differences between an expression and an equation.
![alt text](/filestore/BlogImage/0f212230-d63c-499c-8de5-88d8517b12ee/8449f485-3803-4701-9500-d33856747595Lesson517012019.JPG "matrix")
## Teacher intervention
**Q17. Write 'Multiply f by 8 and subtract 32 to equal 96.' as an equation.**
Pupil A knew the answer to this question verbally, but was not able to enter what she was actually saying. When I informed her of this, she was then able to enter the correct answer.
Pupil B also had difficulty with this question. She kept on typing 5f due to the diagram. When I covered up the diagram, she then got the correct answer.
**Q23. Sarah says, 'I am thinking of a number. I multiply it by 3 and add 17.'
If n is the number Sarah is thinking of, write an formula for her puzzle.**
Pupil C thought that 3n + 17 was 20n. She did not realise that 3n + 17 was different to 3n + 17n, (she thought they were the same thing). We discussed this for several minutes, and I showed her other examples on paper to get the point across.
**Q29. The length of a rectangle is x. Its width is 5 centimetres less than its length.
Write an equation for the rectangle's perimeter using the variables P (perimeter) and x (length).**
Several pupils entered x+x+x-5+x-5 and did not realise you had to simplify this. Also, they didn't understand to start with P =. Instead, they just wrote the 4x - 10 part.