Category Archives: Problem Solving

256. Health Warning!

Test reviews/reflections … possibly one of the dullest type of lesson! I ask my students to write a list containing three topic specific things they are proud of, three topic specific things that could be improved upon and any ‘Maths Health Warnings’.mathswarning

Image designed at: http://www.speedystamps.co.uk/

What is a ‘Maths Health Warning’?
I’m glad you asked!
They are silly mistakes, mild misconceptions, badly managed arithmetic and not reading the questions. They are bad for your mathematical health because a minor error at the start of a solution can cripple your chances of correctly solving a problem. These errors can infect any topic from grade G data to A* trigonometry.

I discuss common mistakes and it is up to pupils to decide which health warnings they need – this usually involves highlighter/feltpens and circling/starring the issue.

Examples
Having recently marked topic tests from grade E to A, here is a list of transferable mistakes:

  • Not reading the question!
  • Mismanaging negatives
  • Not using the correct equipment for diagrams
  • Expanding brackets correctly and simplifying incorrectly
  • Mishandling decimals in calculations
  • Not reading the question (it happens a lot)!
  • Rounding the calculation too soon
  • Rounding incorrectly to decimal places/significant figures
  • Typing a calculation into a calculator incorrectly
  • Forgetting there are only 60mins in an hour
  • Not using 2dp for money
  • ….this list could get rather long!

Once students start identifying these types of errors themselves, they become more aware of them in their classwork, homework and assessments. This results in improved understanding and progress.

Next steps

You might want to generate your own ‘Maths Health Warning’ stampers or stickers. You could put warnings in your students books and ask them to identify the error.

255. Resource of the Week

I can’t wait to share the resource I stumbled across this week. I had planned a lesson on distance-time graphs, for my Foundation GCSE class, at home and went into school to print out my resources, only to discover the photocopier was broken!  I went to the TES website and found this brilliant set of resources on distance-time graphs. They required a small amount of printing, but engaged a ‘bouncy’ class very effectively!

Hare-and-The-Tortoise-Distance-time-graphs by lttmaths.

  • The PowerPoint presentation takes you through interpreting graphs. It also supports my teaching method of ‘every graph tells a story’.
  • The Disney cartoon (from 1934) entertained the class and introduced the idea that graphs are not just A to B in the fastest time. Although they were a little concerned about the age gap between the Hare and the schoolgirl bunnies he was flirting with.
  • My usually less than enthusiastic class did an outstanding job explaining what the graphs showed, as shown by all these annotations:

distance time graphs

  • The activities and plenaries are a perfect fit.

Go and try out these resources next time you are working with distance-time graphs!

254. Laminated Feedback

I love tessellation! You get the chance to be a bit more artistic and creative. I’m a fan of this particular website too: http://www.tessellations.org/ The website has examples of fine art and student work, how to make different types of tessellations and even 3D tessellations.

Now I’m sure we all often use tessellation as a homework – the ‘Finish off your amazing classwork at home’ kind of thing. When collection time comes you get many different standards of work:

  • Beautiful felt pen designs
  • Beautiful coloured pencil designs
  • Designs that started well and went a touch wobbly when they were rushed
  • Beautiful, but slightly wrong designs
  • Beautiful to begin with, then got crushed in a bag designs
  • Didn’t do the homework designs

All, apart from the last case, can be enhanced and developed with the use of a laminator and a guillotine.

Why a guillotine?
To trim off rough edges and forgiveable errors where the student got muddled at the edge of the paper.

Why a laminator?
Laminating the work flattens out any crushed/folded bits. It also preserves decorative edgings when the work is on the wall.

Students who spend ages with coloured pencil produce lovely work which just doesn’t stand out:

image

However, laminating it makes the colours more vibrant:

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It’s hard to show the difference in a photograph, but take my word for it – it works!

You mentioned feedback?
It’s tricky to feedback on visual work without writing an essay or scrawling over the work. A simple solution is to use a marker pen to write on the laminate. Hand out the laminated work and board pens. Students can critique each other’s work by drawing around the individual tiles and annotating them, any errors can be highlighted and other comments made. The wipe-off pens make it less threatening and avoid permanent marks. The great thing is that the original work is not damaged and all comments can be removed with a damp cloth. Of course if you are using this for a wall display teachers may want a more permanent pen for feedback.

Final display

These works of art will be more hardwearing than your average display. You could hole-punch the corners and tie them together to make a wall hanging. You could laminate work back to back and hang them from the ceiling. You could even use the wall hanging as a temporary curtain if you have a rail in your room.

253. Picture of the week

Here is a quick photo prompt starter for you:
What does this picture make you think of?
image

If you said favourite colour bar-chart or line graph, you’d be wrong.

The shorter the bar, the more popular the colour.

However turn it upside down and here is your line graph:

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The heights of the blue bars are the amount of each colour used – hence more popular.

251. Safe as trees

Here’s a two in one post for you, with a wooden theme:

safecracker

Tree 1

This fascinating wooden puzzle is available on Etsy. Each line has to add up to 50 – simple? Not as easy as you’d think. A perfect classroom extension puzzle or gift for a puzzle fanatic!

Tree 2

A little starter on logarithms, with a touch of safecracking too!

Crack the safe Logarithms

The questions are sourced from an A-Level textbook – why not make your own textbook tasks more interesting by creating your own safecrackers on the board? Five minutes prep = puzzle fun!

250. Crack the Circle

Here’s a quick resource for consolidating and revising the area and perimeter of circles and semi-circles.

Circles Crack the Safe (pdf)

Pupils complete the worksheet then work out the code. I personally like having a clear glass Kilner-style jar with a combination padlock at the front of the class … with a little treat for the class to aim for securely locked inside!

248. Fair decorations

Here is a quick cake conundrum for you.

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Two girls are decorating the christmas cake. It is a square fruit cake. They share the icing such that one girl ices the top and one face. The other girl ices the remaining three faces. What possible dimensions of the cake will make the icing areas equal?