Arithmetic Grade Four

Lesson One hundred and ten: Rounding to Nearest 10th


At this point you should remember how to round to the nearest 10 and the nearest 100. Here's a little review of rounding to the nearest 10.

  66 -> 70		122 -> 120		139 -> 140

 219 -> 220		 61 -> 60		988 -> 990

 543 -> 540		 17 -> 20		999 -> 1000

Rounding to the nearest 10th isn't much more difficult. (Remember that the tenths column is the first column to the right of the decimal point and that the hundredths column is to the right of the tenths column.) Here are a few examples:

  1.22 ->  1.2		1.35 -> 1.4		33.44 -> 33.4

  3.55 ->  3.6		2.03 -> 2.0		4.11 -> 4.1

  5.67 ->  5.7		2.93 -> 2.9		9.88 -> 9.9

Rules for rounding to nearest 10th :
  1. If the number in the hundredths column is 4 or less round down. Example: 4.53 -> 4.5.
  2. If the number in the hundredths column is 5 or more round up. Example: 1.45 -> 1.5.
Special Case:

If you have a number like 4.95 you have to remember that it will have to round up to 5.0. Many times students are confused by this situation.

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