Measurement - Capacity

Capacity and volume tell us how much liquid a container can hold. When you pour milk into a glass or fill a bucket with water for a bath, you are working with volume and capacity!

• Comparing Vessels Using Spatial Terms: Before using numbers, we can compare containers simply by looking at their sizes:
• Holds More: A larger container has a bigger capacity and can hold a greater amount of liquid (e.g., a large swimming pool or a water bucket).
• Holds Less: A smaller container has a tiny capacity and holds a smaller amount of liquid (e.g., a tiny spoon or a juice box).

• Introduction to Standard Metric Units: To measure liquids fairly and precisely across the world, we use two standard metric units:
• Millilitre (\text{mL}): A tiny standard unit used to measure very small amounts of liquid. A single raindrop, a small teardrop, or a single teaspoon holds about 1 to 5\text{ mL}.
• Litre (\text{L}): A large standard unit used to measure big amounts of liquid. A large carton of milk, a big bottle of soda, or a bucket of water is measured in litres.
• The Golden Metric Rule: It takes exactly 1000 individual millilitres packed together to fill the space of a single 1-litre bottle!

$\mathbf{1\text{ L} = 1000\text{ mL}}$

• Measuring Volume Using Marked Tools: We can find the exact volume of a liquid by pouring it into marked kitchen cups or laboratory measuring cylinders. To read the measurement accurately:

1. Place the container flat on a steady level table.

2. Look closely at the liquid line straight at eye level.

3. Read the number marking that aligns with the top surface of the liquid.

• Practical Context Problems: Using simple addition and subtraction skills to solve real-world liquid stories, like combining juice recipes or tracking water left in a bottle.