1 out of 3
By selecting digits for an addition grid, what targets can you make?
1 out of 3
What happens when you add a three digit number to its reverse?
2 out of 3
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?
2 out of 3
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
2 out of 3
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
2 out of 3
Where should you start, if you want to finish back where you started?
3 out of 3
3 out of 3
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?
3 out of 3
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.
2 out of 3
Can you explain the surprising results Jo found when she calculated the difference between square numbers?
