1. (Have you ever heard/ Did you ever hear) about continued fractions?
2. We (have started/ started) learning fractions when we were at school.
3. By the end of the lecture the students (had learnt/ has learnt) that in Higher Mathematics a fraction is viewed as an element of a field-of fractions.
4. I (have looked up/ looked up) in a dictionary just now the meaning of the word ‘a solidus’(a slanting line).
5. She just (has written/ wrote) this mixed number in another way; i.e. as an improper fraction.
6. She (will have studied/ will study) carefully the chapter about complex fractions by the end of the week.
7. When you come back I (will have divided/ have divided) these fractions using the rule “invert and multiply”.
8. I need to subtract two fractions but I (haven’t got/ didn’t get) the least common denominator yet.
9. Before he solved the problem he (had had to/ have had to) convert the repeating decimals into fractions.
10. You (have remembered/ remembered) since school that a fraction is in its lowest terms when its numerator and denominator have no common factor other than one.