The girls were looking at equations with unknowns, e.g 2x+5=9
I used smarties to replace the x in the equations.
So I'd put 2 smarties(on the paper) +5 =9.
And posed the question, what is each smartie worth?
For example, if they'd used blue smarties, they then wrote an equation with b.
5B + 12 =62,
So the blue smartie had been given a value of 10.
My husband had never heard the phrase 'Only smarties have the answer'
Do you remember this ad from the 90's?