well you already know how many times 22 can go into 42, it's 1. 42 - 22 is 20, drag down the 5 now it's 205. then ask yourself how many times can 22 go into 205, i would be 9. 9 x 22 = 198, drag down the 6 = 1986. then 22 can go into 1986, 9 times so the answer would be 1.93 rounded to 1.9
I KNOW THIS IS NOT ESTIMATION BUT HOPE IT HELPS....
