Round whole numbers

A teacher with 36 students orders 40 textbooks, he has rounded the actual number to the
nearest ten because 36 is closer to 40 than it is to 30.  We say 36, rounded to the nearest
10, is 40. This process is called _________

When a geologist says that the height of Alaska’s Mount McKinley is “about 20,300 feet,” she has rounded to the nearest hundred because its actual height of 20,320 feet is closer to 20,300 than it is to 20,400. We say that 20,320, rounded to the nearest hundred, is 20,300. This process is called _________.

1. To round a number to a certain place value, locate the rounding digit in that place.
2. Look at the test digit, which is directly to the right of the rounding digit.
3. If the test digit is 5 or greater, round up by adding 1 to the rounding digit
   and replacing all of the digits to its right with 0.
4. If the test digit is less than 5, replace it and all of the digits to its right with 0.