Lessons · Nursing · rounding as the problem states
Round as the problem states, and only at the end
The answer is rounded the way the order or the unit's rule says: drops to a whole drop, millilitres to a tenth, or to a hundredth below 1 mL, tablets to a half only when the tablet is scored. Carry the decimals through the arithmetic and round once, at the end.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
What it is for
You cannot count 41.7 drops and an oral syringe has no mark at 3.125 mL. The rounding rule is part of the answer, and it is written down by the unit or given in the problem, never invented at the bedside. On this track the problem always tells you the rule.
How to think about it
Read the rounding rule before you start, so you know what the answer has to look like. Do the arithmetic with all the decimals. Then round once. If the problem says nearest tenth, look at the hundredths digit: 5 or more rounds up.
Worked example
41.666 gtt/min → 42 gtt/minDrops are counted whole. The rule says nearest whole drop, and .666 rounds up.
3.125 mL → 3.1 mLThe rule says nearest tenth. The hundredths digit is 2, so it rounds down.
0.6375 mL → 0.64 mLBelow 1 mL the rule says nearest hundredth, because a 1 mL syringe is marked in hundredths.
7.5 mg / 5 mg per tablet = 1.5 tablets, scoredA half is allowed because the tablet is scored and the problem says so. Unscored, the answer is not a half.
Your turn
The calculator shows 12.46 mL and the rule is nearest tenth. Write the rounded figure.
12.46 mL → mL
Solve one, graded on the server
The trap
Rounding in the middle. 1.666 rounded to 1.7 and then multiplied by 60 gives 102 instead of 100. Carry the decimals through and round once, at the end, the way the rule says.