Max did 19 situps. This is 1/7 as many as Isabel. How many situps did Isabel do?

7 * 19 = ?

Isabel did 133 sit-ups

To find the number of situps Isabel did, we need to divide 19 by 1/7.

Dividing by a fraction is the same as multiplying by its reciprocal. The reciprocal of 1/7 is 7/1.

So, we can multiply 19 by 7/1 to find the number of situps Isabel did:

19 * (7/1) = 133.

Isabel did 133 situps.