Let the unknown number equal x.
(2/3)x = 16
You can get rid of the fractions by multiplying both sides by 3.
3(2/3)x = 16(3)
2x = 48
Then divide both sides by 2.
2/2 = 1 48/2 = 24
x = 24
2/3 of 24 is 16
You can double check by multiplying 2/3 times 24. This is 16. So we are correct.