If it was required to round 352 to the nearest ten, one might choose 350 or 360, but since 352 is closer to 350 than it is to 360 (352 - 350 = 2 and 360 - 352 = 8), 350 is the better approximation of 352.

Also, the number 313 can be rounded off to 300 as the digits at units and tens place form number 13, which is lesser than 50, so we replace 1 and 3 by 0 and write the digit at hundreds place as it is.

Factors of 273 are the list of integers that can be evenly divided into 273. There are overall 8 factors of 273 i.e. 1, 3, 7, 13, 21, 39, 91, 273 where 273 is the biggest factor. The sum of all factors of 273 is 448 and its factors in Pairs are (1, 273), (3, 91), (7, 39), (13, 21).

b) We round the number down to the nearest hundred if the last two digits in the number are 49 or below. In 236, 36 is less than 50. Therefore, 236 rounded to the nearest hundred is 200.

Your choices for rounding 363 to the nearest ten are 360 or 370. 363 is 3 higher than 360, and 7 less than 370. This tells you that its closest to 360, so you would round it to 360.

To be able to round to the nearest hundred by recognizing that numbers 50 and over round up and numbers less than 50 round down. For example, 367 and 425 both round to 400.