How do you make a ballpark estimate for 52-29?

Answer 1

81

Answer 2

Ballpark estimate would be rounding the numbers to the nearest 10. If the number's second number is more than 5, it will go up. But if its 4-0 you round down.

So you change 52 to 50 and 29 to 30.

And if you had to do the ballpark estimate you just do 50 - 30 in your head and you get 20.