Hints for the comparing fractions assignment:

• The first rule should start "if the denominators are the same"
• The explanations for the rules should all include a mention of how the denominator affects the size of the relevant unit fractions
• The explanations for the rules should all include a mention of how the numerator, and hence the number of pieces of unit fraction size affects the size of the relevant fractions
• the third rule could start: if  b - a = d - c