Ron Gwairown always writes numbers down back to front. At school, he was once asked to do the following calculation:
14 x 82
In his exercise book Ron wrote down:
41 x 28
1. What answer did he get?
2. What answer should he have got?
3. Investigate other pairs of calculations of this type? What can you discover?
Topics: Starter  Arithmetic  Investigations  Place Value
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A three digit number multiplied by the same number back to front gives the product
What are the two threedigit numbers?
This puzzle was adapted from the weekly puzzle in the Grange Academy Mathematics Department Newsletter (Thanks Chris Smith)
Teacher, do your students have access to computers such as tablets, iPads or Laptops? This page was really designed for projection on a whiteboard but if you really want the students to have access to it here is a concise URL for a version of this page without the comments: Transum.org/go/?Start=September6 However it would be better to assign one of the student interactive activities below. 

Here is the URL which will take them to a related student activity.