Substitution

This task from Mark Scanlan (Hillhead HS) at first appears to be minimally different practice. However, as is often the case – the task is only as good as the questioning from the teacher.

Questions a and b are the reverse of each other – focusing learners on the commutative law. Similarly for c and d. Connections can be drawn between parts e, f and g. Part h and part i are multiples of parts a and c respectively.

Points to notice: Consider the result of x = -4 substituted into x – 2. What might the we expect the result to be when x = -4 is substituted in 4x-8? Or When x = -4 is substituted into x + 3, what about when we double the value of x and we also double the expression we are substituting into, e.g. x = -8 into 2x + 6?

One comment