Grade 3 Measurement: Liters and Milliliters

Measure liquid volume

What You'll Learn

Choose milliliters or liters for an amount of liquid
Solve one-step problems with liquid volumes in the same unit (3.MD.A.2)

📖Volume

Milliliters measure small amounts of liquid: a teaspoon holds about 5 milliliters. Liters measure big amounts: a large water bottle holds about 1 liter. Add, subtract, multiply or divide amounts that use the same unit.

Worked examples

Real problems from the practice worksheets, solved one step at a time.

Example 1
Would you use milliliters or liters to measure a few drops of lemon juice?
1. Milliliters are for small amounts of liquid (a few drops). Liters are for big amounts (a large water bottle holds about 1 liter).
2. A few drops of lemon juice is a small amount, so use milliliters.
3. The answer is milliliters.
Answer: milliliters
Example 2
A glass has 155 milliliters of milk. Mia pours in 185 milliliters more. How many milliliters of milk are in the glass now?
1. Pouring in more milk adds to what is already there.
2. 155 + 185 = 340.
3. There are 340 milliliters of milk in the glass now.
Answer: 340
Example 3
A fish tank has 21 liters of water. Sam adds 10 liters more. How many liters of water are in the fish tank now?
1. Adding water puts more in the tank: add.
2. 21 + 10 = 31.
3. There are 31 liters of water in the fish tank now.
Answer: 31