u just make the number shorter e.g.
1.7 is rounded off to 2
Ten integers can be rounded off to 280. An infinite number of numbers can be rounded off to 280.
999 of them.
Since numbers equal to or greater than 5 are rounded up, and numbers equal to or less than 4 are rounded down, the largest 4-digit number that can be rounded off to 3000 would be 3004.
15 to 24
3 499
25549
45 to 54
Infinitely many.
35 to 44
245 to 254
The numbers from 75 to 84 are rounded off to 80 to the nearest ten
When rounding off, the rule is, "If the first figure to be discarded is 5 or more then the previous figure is increased by 1. Following this rule then 650 is the result of rounding off numbers in the range 645 to 654. As 650 itself is not rounded off then there are 9 whole numbers that can be rounded to 650.