Most MAP tests are not timed. As amylou explained, the questions will keep being fed and progressively more difficult until the test taker cannot answer similar difficulty questions say, perhaps 3 in a row.

Explain to your child exactly that, it's going to get tough eventually, don't let that frustrate you, it's SUPPOSE to get hard to the point where you don't know anymore. Tell them just to give their best effort, read fully everything, and check their answers. Most MAP tests allow a student to save where they're at and continue at another time if a break is needed or the time period available isn't enough.