A more reasonable estimate would be 15.
No, it is not.
The best estimate is always the exact answer since it is always possible to improve upon any other estimate.
60 x 30 = 1800
It is 30.
60 x 30 = 1800
It is 71 + 30 = 101.
31
290 - 30 = 260
960 x 30 = 28800
About 30 inches
If you added two numbers and got the right total, you didn't need an estimate, reasonable or not.
The answer = 3520
3520.
it is 640 kilometer per hour
The best estimate is always the exact answer since it is always possible to improve upon any other estimate.
5 squared is 25, and 6 squared is 36. So the square root of 30 has to be between 5 and 6. Since 30 is fairly close to midway between 25 and 36, 5.5 would be a reasonable estimate. (My calculator tells me that the answer is approximately 5.477, so 5.5 is quite good.)
6x5=30 sq in I would hope this would be one of the choices.
31.8321