Adding, converting, multiplying and dividing — the whole unit on one paper.
The answer key prints on a separate page.
The unit has three moves in it, taught in roughly this order: adding and subtracting once the denominators already match, then reading a fraction as its decimal, then multiplying and dividing. They look related and are not. Adding keeps the denominator; multiplying changes it; dividing flips the second fraction and then multiplies. A child who is fluent in section 1 and stuck in section 3 has not forgotten fractions — they have met a rule that contradicts the one they just learned.
That is why the sections sit on one paper. A page of twenty identical questions shows whether a procedure stuck; a mixed page shows whether a child can tell which procedure the question is asking for, and that is the thing a unit is finished on.
