A piano teacher has 4 1/2 hours available to teach each night. One lesson will last 3/4 of an hour. How many lessons can the teacher schedule each night?

Step-by-step explanation:

4 1/2 = 9/2

so, the calculation is simply how often 3/4 fits into 9/2.

and that is done by division :

9/2 / 3/4

and as we know, to divide by a fraction is the same as to multiply with the upside-down fraction.

so,

9/2 / 3/4 = 9/2 × 4/3 = (9×4)/(2×3) = 3×2/1 = 6

so, without any breaks the teacher can schedule 6 lessons each night.