Answer
Estimate: 70 million
Exact: 77 million
Work Step by Step
Here
93.6 million pet cats
16.6 million pet birds
To find how many more pet cats are there then pet birds we need to find the difference i.e. subtraction.
First lets find estimate with front end rounding.
93.6 (rounds to) 90
16.6 (rounds to) 20
Estimated more million pet cats then pet birds are : 90 - 20 = 70
Now let's find the final exact answer
93.6
-16.6
____
77.0
Exact 77 million more pet cats are there then pet birds.