same and transformed expressions

a ppt is here

much algebra work might helpfully focus on constructing either:

• equivalent expressions (same but look different, smaller or longer) or 
• transformed expressions (what happens to this when you add 5, multiply by 2)

one important appreciation seems to be that the adding or subtracting changes just one part of an expression (some terms) whereas multiplying or dividing changes the whole expression (all terms)

these tasks intend to focus on these aspects

students are asked to consider (maybe in pairs) why the expressions are the same as the one in the centre:

then create their own

identify the operations