Metric System: Length, Capacity & Mass

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Subject: Mathematics

Semester: 2

Period: 5

Week: 27

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School Name:
Teacher’s Name:
Subject: Mathematics
Grade Level: Grade 4
Date: Week 27
Lesson Duration: 45 minutes
Week & Period: Week 27, Period 5
Topic: Metric System: Length, Capacity & Mass
Sub-topic: Measuring and converting metric units

Learning Objectives
By the end of the lesson, students should be able to:

1. Estimate metric units of length, capacity, and mass.
2. Convert between selected metric units.
3. Apply metric measurements in real situations.

Previous Knowledge
Students already know how to measure using a ruler in centimeters.

Instructional Materials
Mathematics textbook for Grade 4, rulers, measuring tape, weighing scales, measuring cups.

Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher shows a water bottle and asks: “How many liters of water do you think this bottle holds?”

B – Building Knowledge (Main Lesson Body)

Time: 25–30 minutes

🔍 Key Definition (Expanded)

The metric system is a decimal-based system of measurement, meaning that all units are related to one another by multiples of 10. It is used around the world and is simpler to convert than the customary system because of its consistent base-10 structure.

There are three major types of measurement in the metric system:

📏 1. Length (Distance)

• Centimeter (cm) – used for small objects (width of a book, length of a pencil)
• Meter (m) – used for medium distances (height of a door, length of a room)
• Kilometer (km) – used for long distances (length of a road, distance between towns)

✅ Conversions

• 100 centimeters (cm) = 1 meter (m)
• 1,000 meters (m) = 1 kilometer (km)

 

🧪 2. Capacity (Liquid Volume)

• Milliliter (mL) – used for small amounts of liquid (a teaspoon of medicine)
• Liter (L) – used for larger quantities (a bottle of soda, a milk jug)

✅ Conversions

• 1,000 milliliters (mL) = 1 liter (L)

 

⚖️ 3. Mass (Weight)

• Gram (g) – used for light objects (a paperclip, a slice of bread)
• Kilogram (kg) – used for heavier objects (a bag of rice, a backpack)

✅ Conversions

• 1,000 grams (g) = 1 kilogram (kg)

 

🧠 Examples (Expanded)

Object	Estimated Measurement	Unit Type
Pencil	15 cm	Length
Door height	2 m	Length
School building length	25 m	Length
Distance to nearby park	2 km	Length
Small water bottle	500 mL	Capacity
Milk jug	1 L	Capacity
Teaspoon of cough syrup	5 mL	Capacity
Slice of bread	40–50 g	Mass
Loaf of bread	1 kg	Mass
Bag of rice	5 kg	Mass

 

🧍‍♂️ Learners’ Activities (Expanded & Interactive)

1. Hands-On Measuring Stations

Set up 3 stations in the classroom:

• Station 1: Length
• Students use metric rulers and metersticks to measure pencils, notebooks, tables, and classroom width.
• Record in cm and convert to meters.
• Station 2: Mass
• Use a kitchen or digital scale to weigh common classroom objects (e.g., a stapler, book, water bottle).
• Estimate in grams first, then weigh and record.
• Convert between g and kg.
• Station 3: Capacity
• Use measuring cups or graduated cylinders.
• Students estimate and measure water in cups, bottles, and jugs.
• Practice converting mL to L.

 

2. Estimation and Comparison Game

• Students are shown or handed various objects (or images if unavailable).
• They must estimate the measurement and choose the most appropriate unit.
• Example: “How heavy is this stapler? A. 200 g B. 2 kg C. 500 mL”

 

3. Metric Conversion Relay

• In teams, students solve quick conversion problems:
• “Convert 150 cm to meters.”
• “Convert 3.5 kg to grams.”
• “Convert 1,200 mL to liters.”
• First team to finish with correct answers wins.

 

✅ Assessment Checks (Expanded)

Oral/Interactive Questions:

1. “How many grams are in 2 kilograms?” → ✅ 2,000 grams
2. “What unit would you use to measure a bottle of juice?” → ✅ Liters or milliliters
3. “Is a car’s weight measured in grams or kilograms?” → ✅ Kilograms
4. “If a desk is 120 cm long, how many meters is that?” → ✅2 meters

Short Written Assessment Questions:

1. Convert:
   250 cm = ___ m
   b. 4.5 kg = ___ g
   c. 3,000 mL = ___ L
2. Circle the best unit to measure:
   A cat’s weight: g or kg
   b. A glass of juice: L or mL
   c. A soccer field: m or km
3. Estimate and record:
   Your height in cm
   b. Your water bottle’s capacity in mL
   c. Your backpack’s weight in kg

 

📝 Teacher Notes (Expanded & Detailed)

• Emphasize the base-10 system:
• Use number lines and place value charts to reinforce that metric units scale up or down by 10s, 100s, and 1000s.
• Show that conversions involve moving the decimal point, not complicated formulas.
• E.g., 2.5 kg = 2,500 g (move decimal 3 places to the right)
• Visual Aids Help:
• Bring real objects or use images and charts for comparisons.
• Hang posters with conversion tables and unit abbreviations (cm, m, km, g, kg, mL, L).
• Vocabulary Development:
• Teach and reinforce unit names and abbreviations:
• centimeter (cm), meter (m), kilometer (km)
• gram (g), kilogram (kg)
• milliliter (mL), liter (L)
• Encourage Real-World Thinking:
• Ask students to give examples of metric units they’ve seen at home (e.g., soda bottles in L, medicine in mL, food packages in g or kg).
• Assign take-home activities that involve measuring or estimating household items.

 

📘 Optional Homework / Extension Activity

• "Metric Around the House" Worksheet:
  Students find and record 2–3 items at home for each category (length, mass, capacity), estimate their measurements, and identify the appropriate units.

 

C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Metric units are based on multiples of 10 and include length, capacity, and mass.

Evaluation Method (Expanded)
Exit slip/quiz: Students convert 200 cm into meters and 3000 g into kilograms.

Assignment (Expanded)
Measure your classroom door in centimeters and meters. Weigh 3 fruits and record in grams and kilograms.

Follow-up Activity
Students compare their estimations with actual measurements at home.

Differentiation / Inclusive Strategies
Use larger containers and bigger measurement units for hands-on learning.

Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low