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Sunday Afternoon Maths LXVI
Cryptic crossnumber #2Sunday Afternoon Maths LXV
Cryptic crossnumber #1Breaking Chocolate
Square and cube endings
Sunday Afternoon Maths LXIV
Equal lengthsDigitless factor
Backwards fours
Sunday Afternoon Maths LXIII
Is it equilateral?Cube multiples
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In this puzzle, the clues are written like clues from a cryptic crossword, but the answers are all numbers. You can download a printable pdf
of this puzzle here.
1  2  
3  
4  
5 
Across
 Down

Cryptic crossnumber #1
In this puzzle, the clues are written like clues from a cryptic crossword, but the answers are all numbers. You can download a printable pdf of this puzzle here.
1  2  
3  4  
5 
Across
 Down

Breaking Chocolate
You are given a bar of chocolate made up of 15 small blocks arranged in a 3×5 grid.
You want to snap the chocolate bar into 15 individual pieces. What is the fewest number of snaps that you need to break the bar? (One snap consists of picking up one piece of chocolate and snapping it into two pieces.)
Square and cube endings
Source: UKMT 2011 Senior Kangaroo
How many positive twodigit numbers are there whose square and cube both end in the same digit?
Equal lengths
The picture below shows two copies of the same rectangle with red and blue lines. The blue line visits the midpoint of the opposite side. The lengths shown in red and blue are of equal length.
What is the ratio of the sides of the rectangle?
Digitless factor
Ted thinks of a threedigit number. He removes one of its digits to make a twodigit number.
Ted notices that his threedigit number is exactly 37 times his twodigit number. What was Ted's threedigit number?
Backwards fours
Source: FiveThirtyEight
If A, B, C, D and E are all unique digits, what values would work with the following equation?
$$ABCCDE\times 4 = EDCCBA$$Is it equilateral?
Source: Chalkdust issue 07
In the diagram below, \(ABDC\) is a square. Angles \(ACE\) and \(BDE\) are both 75°.
Is triangle \(ABE\) equilateral? Why/why not?