Jugs and Mugs - Conversion of Capacity Units

Capacity is the measure of how much liquid a container can hold. Imagine a large bucket and a small spoon; the bucket has a much larger capacity because it can hold more water than the spoon.

The standard units used to measure capacity are Litre ($L$) and Millilitre ($ml$). We use Litres for larger quantities like a bucket of water or a petrol tank, and Millilitres for smaller quantities like a dose of medicine or a small juice box.

The relationship between the two units is $1$ Litre $= 1000$ Millilitres. You can visualize this by imagining filling a $1$-litre bottle using exactly ten small cups of $100 ml$ each.

To convert Litres into Millilitres, we multiply the number of Litres by $1000$. For example, if you have $5 L$ of water, it is the same as $5 \times 1000 = 5000 ml$.

To convert Millilitres into Litres, we divide the number of Millilitres by $1000$. For instance, $4000 ml$ is equal to $4000 \div 1000 = 4 L$.

When a measurement is given in both Litres and Millilitres, such as $3 L 250 ml$, we first convert the Litres to Millilitres and then add the extra Millilitres. In this case: $(3 \times 1000) + 250 = 3250 ml$.

Measuring tools like measuring cylinders or jugs often have markings (graduations) on the side. A $1 L$ jug might have marks every $100 ml$ or $200 ml$ to help us read the volume of liquid inside accurately.

Estimation is an important skill. For example, a standard tea cup holds about $200 ml$, a water bottle holds about $1 L$, and an eye dropper holds about $1 ml$ to $2 ml$.