### There are 10 results

Broad Topics >

Algebraic expressions, equations and formulae > Difference of two squares

##### Age 14 to 16 Challenge Level:

A 2-Digit number is squared. When this 2-digit number is reversed
and squared, the difference between the squares is also a square.
What is the 2-digit number?

##### Age 14 to 16 Challenge Level:

Can you explain the surprising results Jo found when she calculated
the difference between square numbers?

##### Age 14 to 16 Challenge Level:

Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?

##### Age 14 to 16 Challenge Level:

Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.

##### Age 14 to 16 Challenge Level:

The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = n² Use the diagram to show that any odd number is the difference of two squares.

##### Age 14 to 16 Challenge Level:

Euler found four whole numbers such that the sum of any two of the numbers is a perfect square...

##### Age 14 to 16 Challenge Level:

Prove that if the integer n is divisible by 4 then it can be written as the difference of two squares.

##### Age 14 to 16 Challenge Level:

Take any prime number greater than 3 , square it and subtract one.
Working on the building blocks will help you to explain what is
special about your results.

##### Age 11 to 14 Challenge Level:

A man paved a square courtyard and then decided that it was too
small. He took up the tiles, bought 100 more and used them to pave
another square courtyard. How many tiles did he use altogether?

##### Age 14 to 16 Challenge Level:

Which armies can be arranged in hollow square fighting formations?