The best estimation is 125 because I rounded 25.4 and 5.1 to the nearest whole number and then I multiplied 25 and 5 and got 125. But it also depends on what number what the teacher wanted you to round to, if they wanted you to round it the the tens then the answer would be 300. The answer would be 300 because I rounded 25 and 5 to the nearest tens and got 30 x 10. I then multiplied and got 300. Hope this helps.