By selecting digits for an addition grid, what targets can you make?
What happens when you add a three digit number to its reverse?
Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
Where should you start, if you want to finish back where you started?
How many more miles must the car travel before the numbers on the milometer and the trip meter contain the same digits in the same order?
Three people chose this as a favourite problem. It is the sort of problem that needs thinking time - but once the connection is made it gives access to many similar ideas.
Can you explain the surprising results Jo found when she calculated the difference between square numbers?
