You can find the number with the next lower unit value and the number with the next higher unit value, then determine which is closer. If they are the same distance, we usually consider the higher one to be "closer."
Your number is bracketed by 529 and 530. The distance from 529 is 0.48. The distance from 530 is 0.52, so your number is closest to 529.
Various rules have been developed to make this process a little easier. One such rule is, "If the digit to the right of the units digit is 5 or greater, add 1 to the number. Drop all digits to the right of the units digit." In your number 529.48, the digit to the right of the units digit is 4, so we simply drop all digits to the right of the units digit, leaving 529.
Another rule that can be used is, "Add half the units digit, and drop all digits of the sum that are to the right of the units digit." When we do that to your number, we drop the .98 from the sum 529.48+0.50 = 529.98. That leaves 529.
Your number is bracketed by 529 and 530. The distance from 529 is 0.48. The distance from 530 is 0.52, so your number is closest to 529.
Various rules have been developed to make this process a little easier. One such rule is, "If the digit to the right of the units digit is 5 or greater, add 1 to the number. Drop all digits to the right of the units digit." In your number 529.48, the digit to the right of the units digit is 4, so we simply drop all digits to the right of the units digit, leaving 529.
Another rule that can be used is, "Add half the units digit, and drop all digits of the sum that are to the right of the units digit." When we do that to your number, we drop the .98 from the sum 529.48+0.50 = 529.98. That leaves 529.