We are approaching a palindromic date: January 21st = 21.1.12.
That reflective number 21112 reminded me of an interesting diversion discussed on the Let’s Play Maths Blog.
The diversion is basically a ’can-you-make-all-of-the-digits…’ puzzle.
Here are the rules:
Using only the digits in the year 2012 can you write mathematical expressions for all of the counting numbers 1 to 100.
You may use any mathematical expression, but cannot use a decimal point to make ‘new’ numbers (1.2, for example)
That can be quite a challenge, but, using a simplified version of these ‘rules’, and the full palindromic date instead of just 2012, the challenge becomes more appropriate for primary age children. For a start, many numbers are already there: 1, 2, 11, 12, 20, 21, 22
While others are trivial: 1+2 = 3, 2+2 = 4 … 20/2 = 10 …. 12×2 = 24
This would work successfully for Key Stage 2 children if you challenged them to find only the numbers from 1 to 25, say. Which numbers do they find easily, which are more tricky, which ones are (seemingly) impossible?
Add your comments below.
The Let’s Play Maths Blog had a number of additional limitations, that made the original version of this a much tougher challenge, check out the blog itself for the full details. [Let's Play Maths Blog]
[jbox]Related resources: Puzzles, Mental & Oral[/jbox]
