This problem was designed to explore equivalence of change (ie. if
a $10\%$ decrease isn't the opposite of a $10\%$ increase, what is?
) and to move students towards the important Stage 5 concept:
exponential growth and decay.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities
can be found here.