There is no special trick. Just by looking and by cancellation only. Notice that 22/11 = 2
28/14 = 2
34/17 = 2
40/20 = 2
And then, 2*2*2*2 = 16.
hello , this is my problem : calculate (22*28*34*40)/(11*14*17*20) without using a calculator , i cant calculated without a calculator but with a calculator i get 16 ( google calculator) but how do i do this in my mind and relativly fast? is there a trick of some sort? thank you for your time.