Round 51.65 to the nearest whole number

51.65 to the nearest whole number

After the whole number 51, the next digit is 6, and since this is more than 5. So we round up the 51 to 52.

51.65 ≈ 52  to the nearest whole number.

When rounding, if the number is less than 5, you must round down. If the number is 5 or more, you round up.
You want to round to the nearest whole number so you look at the first number after the decimal point. In this case it is the 6.
So 51.65 to the nearest whole number is 52. Hope this helped :)