680 + 440 = 1120
The ballpark estimate for 439 plus 71 can be simplified by rounding both numbers. Rounding 439 to 440 and 71 to 70 gives us 440 plus 70, which equals 510. Therefore, the ballpark estimate for 439 plus 71 is approximately 510.
439 + 71 = 510
520.
439 + 71 = 439 + 1 + 70 = 440 + 70 = 510. Who needs a ball park estimate when the exact answer is just as easy to find?
nothing at all
234 + 678 = 912
789 + 678 = 1467
678 + 75 = 753
439 + 746 = 1185
567 + 678 = 1,245
87794 + 39357 + 180 + 439 = 127,770
9 plus 2 plus 2 plus 45-678 is equal to -620.