What is the smallest number with exactly 14 divisors?
Many numbers can be expressed as the sum of two or more consecutive integers. For example, 15=7+8 and 10=1+2+3+4. Can you say which numbers can be expressed in this way?
Do you know a quick way to check if a number is a multiple of two? How about three, four or six?
Here is an alternative and more unusual version of the "Think of a Number" trick which you may have heard of before.
From your answer I can work out both your numbers very quickly. How?
Choose some different pairs of numbers and repeat the process.
Can you figure out how the trick works?
Click here for a poster of this problem.