Question

Khabib had a 1.5 kg bag of potting soil he used 420 grams of soil to potted plants how many kilograms of soil are left in the bag write your answer with two decimal places

Answer 1

We need to have every quantity with the same units. Since 1kg=1000g, then

$420g\frac{1\operatorname{kg}}{1000g}=0.42\operatorname{kg}$

Then, he now has

$1.5\operatorname{kg}-0.420\operatorname{kg}=1.08kg$

Then, there is 1.08 kg of soil left in the bag.