The expression is 23.6 of 90.

The percent is 23.6 and the whole is 90. You need to find the part.

Let n represent the number.

Part = percent whole

n = 0.23690              (Substitute percent = 0.236 and whole = 90)

n = 21.24                     (Multiply: )

21.24 is 23.6 of 90.