Learn on PengiEureka Math, Grade 4Chapter 7: Metric Unit Conversions

Lesson 3: Express metric capacity measurements in terms of a smaller unit; model and solve addition and subtraction word problems involving metric capacity.

In this Grade 4 Eureka Math lesson from Chapter 7, students learn to convert metric capacity units (liters and milliliters) to a smaller unit and use that skill to solve addition and subtraction word problems involving metric capacity. Students draw tape diagrams and apply algorithms or simplifying strategies to model and solve multi-step problems with mixed units. The lesson builds directly on prior work with metric length and mass conversions, reinforcing how place value connects across all metric unit types.

Section 1

Converting Between Liters and Milliliters

Property

The fundamental relationship between liters (L) and milliliters (mL) is:

1 L=1,000 mL1 \text{ L} = 1,000 \text{ mL}
To convert a measurement from liters to milliliters, multiply the number of liters by 1,000.

Examples

Section 2

Add Mixed Units of Capacity

Property

To add mixed units of capacity, add the liters and milliliters separately. If the sum of the milliliters is 1,000 or more, regroup 1,000 mL as 1 L. An alternative strategy is to convert all units to milliliters, add, and then convert the result back to mixed units.

Examples

Section 3

Subtracting Mixed Capacity Units with Regrouping

Property

To subtract mixed units where the milliliters in the minuend are less than in the subtrahend, regroup 1 liter as 1,000 milliliters:

A L B mL=(A−1) L (B+1000) mLA \text{ L } B \text{ mL} = (A-1) \text{ L } (B+1000) \text{ mL}

Examples

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Converting Between Liters and Milliliters

Property

The fundamental relationship between liters (L) and milliliters (mL) is:

1 L=1,000 mL1 \text{ L} = 1,000 \text{ mL}
To convert a measurement from liters to milliliters, multiply the number of liters by 1,000.

Examples

Section 2

Add Mixed Units of Capacity

Property

To add mixed units of capacity, add the liters and milliliters separately. If the sum of the milliliters is 1,000 or more, regroup 1,000 mL as 1 L. An alternative strategy is to convert all units to milliliters, add, and then convert the result back to mixed units.

Examples

Section 3

Subtracting Mixed Capacity Units with Regrouping

Property

To subtract mixed units where the milliliters in the minuend are less than in the subtrahend, regroup 1 liter as 1,000 milliliters:

A L B mL=(A−1) L (B+1000) mLA \text{ L } B \text{ mL} = (A-1) \text{ L } (B+1000) \text{ mL}

Examples