List

Short Problems

Quiz Questions
problem

Quiz Questions

Age
11 to 14
Challenge level
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Jack does a 20-question quiz. How many questions didn't he attempt?
Jenny's Logic
problem

Jenny's Logic

Age
11 to 14
Challenge level
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Weekly Problem 52 - 2009
How did Jenny figure out that Tom's cards added to an even number?
Mini Kakuro
problem

Mini Kakuro

Age
11 to 14
Challenge level
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The sum of each column and row in this grid give the totals as shown. What number goes in the starred square?
Newspaper Sheets
problem

Newspaper Sheets

Age
14 to 16
Challenge level
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From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?
Central Sum
problem

Central Sum

Age
11 to 14
Challenge level
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Can you find numbers between 100 and 999 that have a middle digit equal to the sum of the other two digits?
12345
problem

12345

Age
14 to 16
Challenge level
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Repeat a pattern of numbers to form a larger number. Can you find the sum of all the digits?
Digit Deletion
problem

Digit Deletion

Age
11 to 14
Challenge level
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What is the largest number of digits that could be erased from this 1000-digit number, to get a surprising result?
Alberta's Age
problem

Alberta's Age

Age
14 to 16
Challenge level
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Alberta won't reveal her age. Can you work it out from these clues?
Double with 1 to 9
problem

Double with 1 to 9

Age
11 to 14
Challenge level
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Can you find a number and its double using the digits $1$ to $9$ only once each?