Lessons · Pharmacy · pounds to kilograms
Pounds on the chart, kilograms in the order
Weight-based orders are written in kilograms, and there are 2.2 pounds in a kilogram, so pounds divide by 2.2 to become kilograms.
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
The scale in the waiting room reads pounds and the order reads milligrams per kilogram. If the pounds go into the multiplication unconverted, the answer comes out 2.2 times too big, and it will still look like an ordinary number on the label.
How to think about it
Kilograms first, always, before any dose arithmetic starts. Pounds to kilograms divides by 2.2; kilograms to pounds multiplies by it. Then check the size: a kilogram figure is always smaller than the pound figure it came from.
Worked example
1 kg = 2.2 lbThe conversion this track uses. The problem will always state it.
66 lb / 2.2 = 30 kgPounds into kilograms divides. Smaller, as it must be.
176 lb / 2.2 = 80 kgAn adult, the same way.
30 kg x 2.2 = 66 lbThe other direction multiplies, back to where it started.
Your turn
A child weighs 55 lb. Write the line that gives the weight in kilograms.
55 lb / 2.2 = kg
Solve one, graded on the server
The trap
Multiplying by 2.2 instead of dividing. It gives a bigger number, and bigger feels like more careful, and it is the wrong way round. The kilogram figure is always the smaller of the two.