Question

A patient weighs 14 kg and requires drug A at a dose of 5 mg/kg per day. What is the total daily dose for this patient?

Answer 1

`70 mg`

Explanation:

First off is the cancellation of dimensions

`14 kg * 5 (mg)/(kg)=14cancel(kg)*5(mg)/(cancel(kg))=(14*5)mg`

For simplicity you can split 14 up and distribute

`=((10+4)*5)mg=((5(10)+5(4))mg=(50+20)mg`

`=70mg`

Answer 2

`70 mg`

Explanation:

Use the units of measurement to guide as to how to do the calculation.

You need to end up with just `mg`

We are given `color(red)(Kg) and color(green)( (mg)/(Kg))`

If we do this: `color(red)(Kg)color(green)(xx(mg)/(Kg)` we end up with:

`color(green)((color(red)(Kg))/(Kg)xxmg ->(cancel(color(red)(Kg)))/cancel((Kg))xxmg" "` as required

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Doing the same thing with the numbers:

#14 color(white)(.)color(red)(Kg)xx5 color(white)(.) color(green)((mg)/(Kg)) = 70 mg#
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A quick way of calculating `14xx5` is to think of 5 as `10/2`

`10xx14=140 and 1/2xx140=70`