Can you explain the surprising results Jo found when she calculated the difference between square numbers?
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?
Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?
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.