a peanut vendor has 5 kilograms of peanuts left to sell. He puts the peanuts in bags that contain 100 grams each. How many bags of peanuts does he have to sell?

Answer 1

First you want to convert both numbers given into the same unit. We are given one amount in kilograms (kg) and another in grams (g), we want to convert them both to kg or both to g (you want to convert into whatever will give you the easiest numbers to work with).

1kg = 1000g, so we can convert the 5kg of peanuts into grams by multiplying by 1000 (easier than dividing 100 g by 1000 and having to work with decimals). To convert you can setup two division equations equal to each other and solve for the missing variable by cross multiplying. You get 1kg per every 1000g, and you want to know how many grams 5kg will give you. Your equations are therefore 1kg/1000g = 5kg/xg. You now cross multiply to solve for x. You get 1kg*xg = 5kg*1000g. You can cross out the units since they each appear on both sides, so you get 1x = 5*1000, so x = 5000.

Doing the conversion, we now know that we have 5000 grams of peanuts. These peanuts are divided in bags of 100g each, so to determine the total number of bags left to sell, you divide 5000 by 100, and get 50. The vendor therefore has 50 bags of peanuts left to sell.