What's My Number? Trivia Quiz

Answer: 0

A positive number is greater than zero, while a negative number is less than zero (which is indicated by writing it with a - before the digits that represent its magnitude). 0 itself is the only number which is neither greater than zero nor less than zero.

Answer: 6

A perfect number is a positive integer which is the sum of all its proper divisors. Clear as mud? The divisors are the numbers that can divide evenly into a given number, and the proper divisors are smaller than the original number. The divisors of 6 are 1, 2, 3 and 6 (since 6 = 1x6 and 6=2x3). The proper divisors are 1, 2 and 3. The sum of these three numbers is 1+2+3 = 6. This is the smallest number for which it works:
1 - no proper divisors
2 - 1
3 - 1
4 - 1+2 = 3
5 - 1

Answer: 2

A point has no dimensions. If a point is translated in a single direction, the result is a line, which has one dimension. If a line is translated in a direction perpendicular to its length, a plane is produced, which has two dimensions.

Answer: 20

If your Greek is good, you should recognise the prefix used to describe a polyhedron with twenty sides. A regular icosahedron has equilateral triangles for its faces, with five triangles meeting at each of its twelve vertices.

Answer: 15

Triangular numbers are a sequence which can be listed as 1, 3, 6, 10, 15, 21, ... - as you can see, each number is larger than the previous one by an amount which increases by 1 each time. Since this is a tedious procedure if you want to know, say, the 100th one, there is a formula which can be used to calculate it: Tn = n(n+1)/2.

The 100th triangular number is therefore 100x101/2, or 505.

Answer: 6

A cube is a three-dimensional figure made up of 6 squares - a standard die is probably the most familiar example. A cuboid is a similar shape, but with some or all of the faces being rectangles instead of squares - think of a ream of paper, for example.

Answer: 2

A triangle with no equal sides is called a scalene triangle, while one with all three sides equal is an equilateral triangle. As well as names describing the relative lengths of a triangle's sides, they can also be given a name that tells you the size of the largest of the three angles: for an acute triangle, all angles are less than 90 degrees; for a right angled triangle, one angle is 90 degrees; for an obtuse angled triangle, one angle is between 90 and 180 degrees. Since the sum of the three angles in a triangle is always 180 degrees, no one angle can be as large as 180, let alone larger than that.

Answer: 8

The vertices are often referred to as corners in everyday usage, but mathematicians prefer the technical term vertex to refer to a point where two or more faces of a polyhedron meet. For a cube, there are three square faces meeting at each vertex.

Answer: 1

The definition of a prime number is that it is a number greater than one which is divisible only by itself and one. (This definition eliminates a number of mathematical paradoxes that would arise if 1 were included as a prime number.) A composite number is one with at least two proper divisors (two numbers smaller than itself by which it is divisible).

For example, 2 can only be divided by 1 and 2, so it is the smallest prime number; 4 can also be divided by 1 and 2, and is the smallest composite number.

Answer: 4

As described earlier a point can be translated to generate a line, which can be translated to generate a plane. If we only use a segment of the line, we can translate it so as to form a square. If that square is moved upwards, in a third dimension perpendicular to that of the original plane, we can produce a cube. Now, mathematically (if not physically), that same process can be repeated using a fourth dimension that is orthogonal to the cube, called a tesseract.