Directly input "duration" data type into Numbers formula
Divide by text in quotes.

So if you want to divide A1 which contain "1h 30m" by "9m" then use the following function A1 ÷ "9m" (A1 contains "1h 30m"). This is the equivalent of putting "9m" in B1 and then in using the function "A1 ÷ B1" in C3: Both will give you 10 because 9 minutes goes into 1 hour 3 min 10 times.