Consecutive squares
The squares of any 8 consecutive numbers can be arranged into two sets of four numbers with the same sum. True of false?
Problem
The squares of any 8 consecutive numbers can be arranged into two sets of four numbers with the same sum.
True or false?
Getting Started
What do the eight terms total?
What does this tell you about each side of the equality?
What does this tell you about each side of the equality?
Student Solutions
If we take any 8 consecutive numbers:
This means that the terms in $x^2$, in $x$, and the constant term must be split equally.
If we sum the squares of each of the eight consecutive numbers, and then halve the result, this will equal the sum of each of the four terms needed. So adding all the squares we have:
Teachers' Resources
A discussion may be needed on how to represent the eight
consecutive numbers.
Students may square and add terms in an almost random way to start with and it is worth giving them time to play before disucssing what might be a more efiicient method.
Rather than squaring terms on a need-to-know basis - how about suggesting working them all out to save time re-calculating expansions as needed.
Students may square and add terms in an almost random way to start with and it is worth giving them time to play before disucssing what might be a more efiicient method.
Rather than squaring terms on a need-to-know basis - how about suggesting working them all out to save time re-calculating expansions as needed.