maths tricks

this task is used to introduce expressions that 'explain' how mathematical 'tricks' work, reinforcing earlier work on how expressions are written, representing a sequence of operations
it can create some surprise

another value of the task lies in putting words alongside
numbers
diagrams
with algebra

the main powerpoint is here

building on this work students can create expressions that they know simplifies to a simple answer (usually a number)
they can seek to understand how expressions are decoded and how the expression simplifies to a known result

the powerpoint for this is here

a task for a recap powerpoint

extending the idea...