Weekly Problem 25 - 2009

Jack does a 20-question quiz. How many questions didn't he attempt?

Weekly Problem 52 - 2009

How did Jenny figure out that Tom's cards added to an even number?

Weekly Problem 21 - 2008

The sum of each column and row in this grid give the totals as shown. What number goes in the starred square?

Weekly Problem 29 - 2011

From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?

Weekly Problem 53 - 2011

Find a number between 100 and 999 that has its middle digit equal to the sum of the other two digits. Can you find all possibilities?

Weekly Problem 50 - 2011

Repeat a pattern of numbers to form a larger number. Can you find the sum of all the digits?

Weekly Problem 14 - 2010

What is the largest number of digits that could be erased from this 1000-digit number, to get a surprising result?

Weekly Problem 26 - 2011

Alberta won't reveal her age. Can you work it out from these clues?

Weekly Problem 31 - 2011

Can you find a number and its double using the digits $1$ to $9$ only once each?