# A sequences alternative to ‘how many matchsticks’

Sequences. You build up a pattern of squares from matchsticks, getting the pupils to fill in a table of number of squares vs number of matchsticks. You ask them to spot the term-to-term and position-to-term (nth term) rules and feel great if they do.

I’ve taught this lesson a few times at differing ability levels this year and the other day came up with a nice alternative context that really engaged the pupils.

I feel privileged to have experience of working as a structural engineer before becoming a teacher and worked for a fantastic company on some high-profile projects. One of the projects that was designed by some very talented engineers in my office was the new skyscraper in the City of London, Heron Tower. I was fortunate enough to visit the building a few times during construction.

After showing the pupils the picture above I led on to using the bracing pattern on the front of the tower to produce a pattern similar to a conventional matchstick pattern but to match that of the tower. The idea was that we could then say we needed X number of steel columns/beams to make 1 storey of the tower, Y number to make 2 storeys of the tower and and so on. The pupils literally were drawing the bracing pattern of Heron Tower and counting the number of storeys vs the number of pieces of steel used! They then found the nth term rule to give the number of steel pieces required to make a tower of any number of storeys!

The plenary of the lesson was me pretending to be an architect in a design team meeting with the kids who were pretending to be engineers. I asked them ‘if I want to make this tower 30, 50 or 100 storeys tall, how many steel beams and columns will we need?”. They used their nth term rules to tell me!

A keen kid said he’d go away and find an nth term rule to calculate the number of steel beams/columns for the whole 3D building, not just a 2D elevation!

The more I teach, the more I think that to motivate kids to learn we need to think context, context, context…

Wow, love the idea, wish I hadn’t just taught sequences and need to move on …. will definitely use this idea next year, or use this during revision. Thank for sharing

Great idea! Going to try it this week, what age group did you use this with?

interesting activity

But what is your answer?

what is the formula that determines the number of steel beams required to make the front bracing pattern for this building that is n levels high?