Solved Exercises on Measurement Word Problems in Grade 3

Master measurement word problems: length, weight, capacity, and time calculations through these 5 detailed exercises with step-by-step solutions.

Measurement Fundamentals
Length: cm, m | Weight: g, kg | Capacity: mL, L | Time: s, min, hr
Basic Units of Measurement
Key Definitions:

Length: Distance between two points (measured in centimeters, meters)

Weight: How heavy something is (measured in grams, kilograms)

Capacity: Amount a container can hold (measured in milliliters, liters)

Time: Duration of events (measured in seconds, minutes, hours)

Problem-Solving Method:
  1. Read carefully: Understand what is being asked
  2. Identify units: Note the measurements given and needed
  3. Plan: Decide what operations to perform
  4. Solve: Calculate step by step
  5. Check: Verify the answer makes sense
Length Conversion
1 m = 100 cm
Centimeters to meters
Weight Conversion
1 kg = 1000 g
Grams to kilograms
Capacity Conversion
1 L = 1000 mL
Milliliters to liters
Tip 1: Draw pictures to visualize length and distance problems.
Tip 2: Use benchmarks - a paperclip weighs about 1 gram, a liter bottle holds 1000 mL.
Tip 3: When converting, multiply to go from smaller to larger units, divide to go from larger to smaller.
Solution: Exercises 1 to 3
1 Length Word Problem
Exercise 1
Sarah has a rope that is 3 meters long. She cuts off 85 centimeters. How many centimeters of rope does she have left?
Definition:

Length conversion: 1 meter = 100 centimeters

Solution method:
  1. Convert meters to centimeters
  2. Subtract the cut portion
  3. Express final answer in requested unit
Cut here 300 cm total 85 cm cut 215 cm left
Step 1: Convert meters to centimeters

3 meters = 3 × 100 = 300 centimeters

Step 2: Subtract the cut portion

300 cm - 85 cm = 215 cm

Step 3: Verify the answer

215 cm + 85 cm = 300 cm = 3 meters ✓

Sarah has 215 centimeters of rope left.
Final answer:

Sarah has 215 centimeters of rope left.

Applied rules:

• Conversion: 1 meter = 100 centimeters

• Subtraction: Take away the cut portion

• Unit consistency: Work in the same unit throughout

2 Weight Word Problem
Exercise 2
A bag of apples weighs 2 kilograms and 350 grams. If Tom eats 750 grams of apples, how much does the bag weigh now?
Definition:

Weight conversion: 1 kilogram = 1000 grams

⚖️
2 kg 350 g
→ -750 g
= 1 kg 600 g
Step 1: Convert total weight to grams

2 kg 350 g = (2 × 1000) + 350 = 2000 + 350 = 2350 grams

Step 2: Subtract the eaten amount

2350 g - 750 g = 1600 g

Step 3: Convert back to mixed units

1600 g = 1000 g + 600 g = 1 kg 600 g

The bag now weighs 1 kilogram and 600 grams.
Final answer:

The bag now weighs 1 kilogram and 600 grams.

Applied rules:

• Conversion: 1 kg = 1000 g

• Mixed units: Convert to smallest unit first

• Regrouping: Convert back to mixed units if needed

3 Capacity Word Problem
Exercise 3
A water tank has 4 liters and 250 milliliters of water. If 1750 milliliters are poured out, how much water remains?
Definition:

Capacity conversion: 1 liter = 1000 milliliters

🥤
4 L 250 mL
→ -1750 mL
= 2 L 500 mL
Step 1: Convert total capacity to milliliters

4 L 250 mL = (4 × 1000) + 250 = 4000 + 250 = 4250 mL

Step 2: Subtract the poured amount

4250 mL - 1750 mL = 2500 mL

Step 3: Convert back to mixed units

2500 mL = 2000 mL + 500 mL = 2 L 500 mL

There are 2 liters and 500 milliliters of water remaining.
Final answer:

There are 2 liters and 500 milliliters of water remaining.

Applied rules:

• Conversion: 1 L = 1000 mL

• Unit conversion: Convert to smallest unit for calculation

• Regrouping: Express final answer in appropriate units

Solution: Exercises 4 to 5
4 Time Word Problem
Exercise 4
Emma started her homework at 3:45 PM. She worked for 1 hour and 30 minutes. What time did she finish?
Definition:

Time calculation: Add hours and minutes separately, regroup if needed

🕐
3:45 PM
+1h30m
= 5:15 PM
Step 1: Add the hours

3:45 PM + 1 hour = 4:45 PM

Step 2: Add the minutes

4:45 PM + 30 minutes = 4:75 PM

Since 75 minutes = 1 hour and 15 minutes:

4:75 PM = 5:15 PM

Step 3: Verify the calculation

From 3:45 PM to 5:15 PM is exactly 1 hour and 30 minutes ✓

Emma finished at 5:15 PM.
Final answer:

Emma finished at 5:15 PM.

Applied rules:

• Time addition: Add hours and minutes separately

• Regrouping: Convert extra minutes to hours

• Verification: Check the total duration

5 Mixed Measurement Problem
Exercise 5
A carpenter needs 2 pieces of wood. The first piece is 1 meter and 45 centimeters long. The second piece is 85 centimeters long. How long are both pieces together?
Definition:

Mixed measurement: Combine different units by converting to the same unit

1m 45cm
85cm
Total: 230cm
Step 1: Convert first piece to centimeters

1 meter 45 centimeters = (1 × 100) + 45 = 145 centimeters

Step 2: Add both lengths

145 cm + 85 cm = 230 cm

Step 3: Convert back to mixed units

230 cm = 200 cm + 30 cm = 2 meters 30 centimeters

Both pieces together are 2 meters and 30 centimeters long.
Final answer:

Both pieces together are 2 meters and 30 centimeters long.

Applied rules:

• Unit conversion: Convert all measurements to the same unit

• Addition: Add the converted measurements

• Final expression: Convert to mixed units if appropriate

Measurement Laws, Rules, and Formulas
1 m = 100 cm | 1 kg = 1000 g | 1 L = 1000 mL
Conversion Formulas
Key definitions:

Length: Distance between two points (cm, m, km)

Weight: Measure of heaviness (g, kg)

Capacity: Volume a container can hold (mL, L)

Time: Duration between events (s, min, hr)

Complete methodology:
  1. Read the problem: Identify what is being measured
  2. Identify units: Note all given measurements and their units
  3. Plan conversion: Decide which unit to convert to
  4. Perform calculation: Add, subtract, or convert as needed
  5. Check answer: Ensure it makes logical sense
Tip 1: Always convert to the same unit before adding or subtracting.
Tip 2: Use benchmarks: a paperclip ≈ 1g, a juice box ≈ 250mL, a ruler ≈ 30cm.
Tip 3: Draw a number line for time problems to visualize the passage of time.
Tip 4: Remember: bigger unit → smaller unit (multiply), smaller unit → bigger unit (divide).
Common errors: Forgetting to convert units, mixing up operations, not checking if the answer is reasonable.
Key formulas: 1m = 100cm, 1kg = 1000g, 1L = 1000mL, 1hr = 60min, 1min = 60sec.
Essential conversion rules:

• Length: 1 meter = 100 centimeters = 1000 millimeters

• Weight: 1 kilogram = 1000 grams

• Capacity: 1 liter = 1000 milliliters

• Time: 1 hour = 60 minutes = 3600 seconds

Measurement Type Large Unit Small Unit Conversion Factor
Length meters (m) centimeters (cm) × 100
Weight kilograms (kg) grams (g) × 1000
Capacity liters (L) milliliters (mL) × 1000
Time hours (hr) minutes (min) × 60

Questions & Answers

Question: I get confused when solving problems that mix different units like meters and centimeters. How do I know which one to use?

Answer: Great question! Here's the key rule: Always convert to the same unit before doing calculations.

  • If the problem asks for the answer in centimeters, convert everything to centimeters first.
  • If the problem asks for meters, convert everything to centimeters then convert the final answer to meters.
  • It's usually easier to work with the smaller unit (centimeters instead of meters).

Example: For 1 meter + 50 centimeters:

Convert 1 meter to centimeters: 1 m = 100 cm

Then add: 100 cm + 50 cm = 150 cm

If needed, convert back: 150 cm = 1 m 50 cm

Question: When I solve time problems, I sometimes forget to carry over the minutes when they go over 60. How can I avoid this mistake?

Answer: This is a very common mistake! Here's a foolproof method:

  • Step 1: Add hours and minutes separately
  • Step 2: If minutes ≥ 60, subtract 60 from minutes and add 1 to hours
  • Step 3: Repeat Step 2 if needed

Example: 2:45 + 1:35

Hours: 2 + 1 = 3

Minutes: 45 + 35 = 80

Since 80 ≥ 60: 80 - 60 = 20 minutes, add 1 hour

Final answer: 4:20

Draw a timeline to visualize the process!

Question: I'm having trouble remembering the conversion factors. Is there a way to remember them easily?

Answer: Yes! Here are some memory tricks:

  • Length: Think "Meter Monster" - a meter is big, so it takes 100 little centimeters to make one big meter
  • Weight: "Kilo" means thousand - so 1 kilogram = 1000 grams
  • Capacity: "Liter" sounds like "little" - but it's actually big! It takes 1000 little milliliters to fill one big liter
  • Time: "Sixty" appears twice - 60 seconds in a minute, 60 minutes in an hour

Practice tip: Write the conversions on a small card and review them daily until they become automatic. The more you use them, the easier they'll become!