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problem
3 out of 3
ABC
7 to 11
3 out of 3
In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication?
problem
1 out of 3
Conical Bottle
14 to 16
1 out of 3
A right circular cone is filled with liquid to a depth of half its vertical height. The cone is inverted. How high up the vertical height of the cone will the liquid rise?
problem
2 out of 3
Square Triangle
11 to 14
2 out of 3
How many triangles have all three angles perfect squares (in degrees)?
problem
3 out of 3
Squeezed In
14 to 16
3 out of 3
Weekly Problem 9 - 2017
What integer $x$ makes $\frac{x}{9}$ lie between $\frac{71}{7}$ and $\frac{113}{11}$?
problem
1 out of 3
Isometric Rhombuses
11 to 14
1 out of 3
Weekly Problem 31 - 2016
The diagram shows a grid of $16$ identical equilateral triangles. How many rhombuses are there made up of two adjacent small triangles?
problem
3 out of 3
Magic Octahedron
11 to 14
3 out of 3
Weekly Problem 20 - 2010
You have already used Magic Squares, now meet a Magic Octahedron...
problem
2 out of 3
Corner Cut
11 to 14
2 out of 3
Weekly Problem 23 - 2017
Three small equilateral triangles of the same size are cut from the corners of a larger equilateral triangle. What is the side length of the small triangles?
problem
3 out of 3
Traffic Jam
14 to 16
3 out of 3
Emily's journey home took 25% longer than usual. By what percentage was her average speed reduced?
article
Enriching Data Handling
This article for teachers looks at some suggestions taken from the
NRICH website that offer a broad view of data and ask some more
probing questions about it.