Teaching Surds

My introduction to surds this year was by setting a problem to my class:

Calculate the exact value of the length of each missing side:

surds intro

Initially the class knew exactly where to start. Pythagoras. Great. The problem arose when calculating the length of the hypotenuse of the red triangle. The class wanted a calculator. This led to a discussion about exact values and accuracy.

Then I set the class the challenge of drawing the Spiral of Theodorus and to calculate the hypotenuse of each triangle and also to calculate the area of each triangle. Continue reading

Factors and Multiples

I want to share a few different activities that I use with pupils when working on factors and multiples.

  • Finding the highest common factor. This is a problem solving activity I made to provide some extra challenge when finding the highest common factor. Working in small groups the pupils have to match a pair of numbers and a highest common factor. The trick is that there are different sets of numbers which will give the same highest common factor. I found that this tested the perseverance of my pupils.

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