Mathematical Miscellany #32

A nice little starter from Transum, Small Satisfaction. I do like the related activities, I know some of my students will do this first level quickly, the second and third levels will provide them with something to think about, or perhaps the alternative, Satisfaction.

Remember that Transum provides starters for students all the way through to Avanced level.

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A divisibility test for 7…
Staying with Transum, Divisibility Tests 2-12 provides a handy summary of divisibility tests. What really caught my eye here is the divisibility test for 7. Scroll down the page for the comment from Transum which tells the story of the origins of the test – a 12-year-old student. And note the proof – something for our A Level students perhaps!

Note the exercises to practise using the divisibility tests. Delightfully Divisible will keep everybody busy! See also, from Plus magazine – Finding the nine. (There is a link to a very clear solution in the video).

Mathisfun is an attractively presented site, the divisibility rules are clearly explained and if you scroll to the end of the page you will see multiple-choice questions to try.

Alternative tests for 7 exist, but I like Chika’s Test!

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The page on the divisibility tests for 7 is a reminder of the site – Mudd Maths Fun Facts. This searchable collection of Mathematics fun facts from Harvey Mudd College Math Department make ideal lesson starters or perhaps useful for those odd moments. Note the search on the left, it is possible to search by topic, difficulty level and keywords.

For example, try:

• Multiplication by 11
• Difference of Squares
• Magic 1089
• Squares Ending in 5 
• Multiplying Complementary Pairs
• Kaprekar’s Constant

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A blast from the past for many teachers perhaps, from MathsFrame, the ITPs have been made available for modern browsers – no Flash needed. Developed in 2002 to help with the teaching of maths in UK Primary Schools, the National Numeracy Strategy Interactive Teaching Programs cover many areas of numeracy including number, shape, measure and statistics.

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To finish this collection, some Number Puzzles from Mathisfun.

Note the complete Mathisfun Puzzle Index.