List

Exploring and Noticing - Short Problems

What Two ...?
problem

What Two ...?

Age
7 to 11
Challenge level
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56 406 is the product of two consecutive numbers. What are these two numbers?
Royal Arm Wrestling
problem

Royal Arm Wrestling

Age
11 to 14
Challenge level
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How many arm-wrestles will there be in the royal arm wrestling championship?
Suit Sequence
problem

Suit Sequence

Age
11 to 14
Challenge level
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A pattern repeats every six symbols. What are the 100th and 101st symbols?
Out of Sync
problem

Out of Sync

Age
11 to 14
Challenge level
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Albert Einstein could see two clocks which were out of sync. For what fraction of the day did they show the same time?
Take a Leaf
problem

Take a Leaf

Age
11 to 14
Challenge level
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An examination paper is made from five pieces of paper. What is the sum of the other page numbers that appear on the same sheet as page 5?
Halloween Day
problem

Halloween Day

Age
11 to 14
Challenge level
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One year there were exactly four Tuesdays and four Fridays in October. On what day of the week was Halloween.
How many Rectangles?
problem

How many Rectangles?

Age
11 to 14
Challenge level
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By drawing 5 horizontal and four vertical lines, one can form 12 rectangles. What is the greatest number of rectangles that can be formed by drawing 15 lines?
Knockdown
problem

Knockdown

Age
11 to 14
Challenge level
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Weekly Problem 51 - 2016
Pegs numbered 1 to 50 are placed in a row. Alternate pegs are knocked down, and this process is repeated. What is the number of the last peg to be knocked down?
Too Close to Call
problem

Too Close to Call

Age
11 to 14
Challenge level
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Weekly Problem 24 - 2012
Can you put these very close fractions into order?
Almost Constant Digits
problem

Almost Constant Digits

Age
11 to 14
Challenge level
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How many 10-digit numbers containing only 1s, 2s and 3s can you write?
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?
Day of the Triffids
problem

Day of the Triffids

Age
14 to 16
Challenge level
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Jasmine buys three different types of plant. How many triffids did she buy?
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?
Collatz-ish
problem

Collatz-ish

Age
14 to 16
Challenge level
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A sequence is generated using these rules. For which values of n is the nth term equal to n?
Back in Time
problem

Back in Time

Age
14 to 16
Challenge level
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How many times a day does a 24 hour digital clock look the same when reflected in a horizontal line?
Oldest and Youngest
problem

Oldest and Youngest

Age
14 to 16
Challenge level
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Edith had 9 children at 15 month intervals. If the oldest is now six times as old as the youngest, how old is her youngest child?