Rounding
Rounding is important in medication administration as syringes and other devices might not be accurate to the thousandths place, or sometimes even the hundredths place.
When rounding, always look at the number to the very right of the place you are wishing to round. To round 3.756 to the nearest tenth, we will look at the hundredths place to determine if the number in the tenths place will be rounded up or down. If the number to the right is 5 or greater, we round up. If it is 4 or less, we round down (we leave the rounded number as is).
Example: Round 5.67 to the nearest tenth. Is the number in the hundredths 5 or greater? It is a 7, so we will round the number in the tenths place up. The answer is 5.7
Example: Round 0.445 to the nearest hundredth. We need to look at the number in the thousandths place. It is a 5, therefore we round the number in the hundredths place up… 0.45
Example: Round 2.348 to the nearest tenth. The number in the hundredths place is 4 or less, so we don’t round up, we round down… 2.3
Example: Round 0.95 to the nearest tenth. The number in the hundredths place is 5, so we round the tenths place number up. In this case, the 9 will round up to 10, however, since each decimal place can only have one digit, you have to bump up to the next place over- 0.(10) becomes 1
When doing simple math equations with decimals, do not round until you have your final answer. If I add 3.55 and 4.95, and the final answer needs to be rounded to the tenth, I will add the numbers first, then round the final answer.
3.55 + 4.96 = 8.51… rounded to the nearest tenth, we would have 8.5 as our answer.
If we mistakenly rounded the numbers before the addition, the answer would be incorrect…
3.6 + 5 = 8.6
Example: Add the numbers and round the answer to the nearest hundredth
6.673 + 3.252 Let’s add the numbers first… giving us 9.925, then let’s round to the nearest hundredths… 9.93
Follow this basic rule for rounding in nursing: If the final answer is less than 1, then round to the hundredths. If the final answer is greater than 1, then round to the tenths. However, if the problem states to round to a certain place, always follow the instructions given.
Complete these practice problems, using nursing rounding rules
Round 15.45
15.5 Round to tenths because number is greater than 1
Round 25.667
25.7 Round to tenths
Round 0.675
0.68 Round to hundredths because number is less than 1
Round 0.125
0.13 Round to hundredths
0.5 x 1.5
0.75 0.5 times 1.5 is 0.75, number is already at the hundredths, no need to round
2.5 x 12.5
31.3 2.5 times 12.5 is 31.25... since number is above 1, we round to the tenth
Time to look at the metric system