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.
This problem is in two parts. The first part provides some building blocks which will help you to solve the final challenge. These can be attempted in any order. Of course, you are welcome to go straight to the Final Challenge without looking at the building blocks!
Click to reveal any of the questions below to get started.
Question A
What happens when you multiply the numbers either side of it?
For example, if you choose 7, work out 6×8. Repeat several times.
Notice anything interesting? Convince yourself it always happens.
Question B
Question C
Multiply them together and record the result. Repeat several times.
Notice anything about your results?
Start with numbers other than 120. Does the same thing always happen? Convince yourself.
Question D
Multiply them together and record the result. Repeat several times.
Notice anything interesting? Convince yourself it always happens.
FINAL CHALLENGE
Notice anything interesting? Convince yourself it always happens.
Age 14 to 16