Milligrams

In your book, Maths Mela (Chapter 8), we ask: how much does an ant weigh? An ant is so light that even a gram is far too big to measure it. Ants weigh between 1 milligram and 5 milligrams. Yet an ant can carry much more than its own weight!

A milligram (mg) is a very small unit of weight. 1 g = 1,000 mg. So a gram is 1,000 times heavier than a milligram. We use milligrams for very light things, like the medicine in a tablet. Gold ornaments are weighed in grams and milligrams, because even a little gold is worth a lot of money.

Changing g into mg is just like changing kg into g: multiply by 1,000. A sugar sachet of 5 g is 5,000 mg. 4 g = 4,000 mg, so an ornament of 4 g 100 mg weighs 4,000 mg + 100 mg = 4,100 mg. A goldsmith's ornament of 10 g 500 mg weighs 10,500 mg.

To compare weights in g and mg, change them to the same unit. Is 9,000 mg more than 90 g? 9,000 mg is only 9 g, so 9,000 mg < 90 g. Which is heavier, 2,010 mg or 2 g 100 mg? 2 g 100 mg = 2,100 mg, and 2,100 mg is more than 2,010 mg. So 2,010 mg < 2 g 100 mg.