Solved Exercises on Comparing Lengths in Grade 1 (Year 3 Worksheets)

Master comparing lengths: measuring with standard units, comparing using centimeters and meters, solving length problems with addition and subtraction through these 5 detailed exercises.

Solution: Exercises 1 to 3
1 Unit conversion worksheet
Exercise 1
Complete the conversions: 2m = ___cm, 150cm = ___m___cm, 3m 25cm = ___cm
Definition:

Unit conversion: Changing measurements from one unit to another

Relationship: 1 meter = 100 centimeters

Conversion method:
  1. To convert meters to centimeters: multiply by 100
  2. To convert centimeters to meters: divide by 100
  3. For mixed units: convert meters to centimeters, then add
1 meter = 100 centimeters
Step 1: 2m to cm

2m = 2 × 100 = 200cm

Step 2: 150cm to m and cm

150 ÷ 100 = 1 remainder 50, so 150cm = 1m 50cm

Step 3: 3m 25cm to cm

3m = 3 × 100 = 300cm, then 300 + 25 = 325cm

2m = 200cm
150cm = 1m 50cm
3m 25cm = 325cm
Final answer:

2m = 200cm, 150cm = 1m 50cm, 3m 25cm = 325cm

Applied rules:

• Multiplication: To convert meters to centimeters, multiply by 100

• Division: To convert centimeters to meters, divide by 100

• Combination: For mixed units, convert and add

2 Addition worksheet
Exercise 2
Solve these: 45cm + 32cm = ___, 1m 20cm + 80cm = ___, 2m 50cm + 1m 75cm = ___
Definition:

Length addition: Adding lengths together when combining objects

Unit consistency: Add like units (cm with cm, m with m)

Step 1: 45cm + 32cm

45 + 32 = 77cm

Step 2: 1m 20cm + 80cm

First convert to same units: 1m 20cm = 120cm, then 120 + 80 = 200cm = 2m

Step 3: 2m 50cm + 1m 75cm

Add meters: 2 + 1 = 3m, add centimeters: 50 + 75 = 125cm = 1m 25cm, total = 4m 25cm

45cm + 32cm = 77cm
1m 20cm + 80cm = 2m
2m 50cm + 1m 75cm = 4m 25cm
Final answer:

45cm + 32cm = 77cm, 1m 20cm + 80cm = 2m, 2m 50cm + 1m 75cm = 4m 25cm

Applied rules:

• Like units: Always add centimeters with centimeters and meters with meters

• Conversion: If sum of centimeters ≥ 100, convert to meters

• Regrouping: 100cm = 1m

3 Subtraction worksheet
Exercise 3
Solve these: 95cm - 28cm = ___, 3m - 1m 50cm = ___, 5m 10cm - 2m 85cm = ___
Definition:

Length subtraction: Finding the difference when removing part of an object

Borrowing: Converting 1m to 100cm when needed

Step 1: 95cm - 28cm

95 - 28 = 67cm

Step 2: 3m - 1m 50cm

Convert 3m to 2m 100cm, then 2m 100cm - 1m 50cm = 1m 50cm

Step 3: 5m 10cm - 2m 85cm

Convert 5m 10cm to 4m 110cm, then 4m 110cm - 2m 85cm = 2m 25cm

95cm - 28cm = 67cm
3m - 1m 50cm = 1m 50cm
5m 10cm - 2m 85cm = 2m 25cm
Final answer:

95cm - 28cm = 67cm, 3m - 1m 50cm = 1m 50cm, 5m 10cm - 2m 85cm = 2m 25cm

Applied rules:

• Like units: Subtract centimeters from centimeters and meters from meters

• Borrowing: When subtracting centimeters, convert 1m to 100cm if needed

• Regrouping: 1m = 100cm for borrowing purposes

Worksheet Templates & Practice Problems
Conversion Practice

2m = ___cm

350cm = ___m___cm

1m 75cm = ___cm

Addition Problems

45cm + 23cm = ___

1m 30cm + 70cm = ___

2m 45cm + 1m 65cm = ___

Subtraction Problems

80cm - 35cm = ___

4m - 1m 25cm = ___

3m 15cm - 1m 90cm = ___

Comparison Problems

2m ___ 180cm

1m 50cm ___ 155cm

3m 25cm ___ 320cm

1 \text{ meter} = 100 \text{ centimeters}
Key Conversion Formula
Key definitions:

Worksheet: A practice sheet with problems to solve

Standard unit: A consistent way to measure length

Conversion: Changing measurements from one unit to another

Mixed units: Measurements with both meters and centimeters

Worksheet completion method:
  1. Read carefully: Understand what operation is needed
  2. Check units: Ensure all measurements are in the same unit
  3. Perform calculation: Add, subtract, or convert as needed
  4. Verify answer: Check if the answer makes sense
Tip 1: Always convert to the same unit before adding or subtracting.
Tip 2: Remember: 1 meter = 100 centimeters.
Tip 3: When subtracting, borrow from meters if needed (1m = 100cm).
Tip 4: Check your work by doing the opposite operation.
Solution: Exercises 4 to 5
4 Comparison worksheet
Exercise 4
Fill in the blanks with >, <, or =: 2m ___ 200cm, 1m 75cm ___ 180cm, 3m 50cm ___ 3m 45cm
Definition:

Comparison symbols: > (greater than), < (less than), = (equal to)

Unit consistency: Compare measurements in the same unit

Step 1: 2m vs 200cm

Convert 2m to cm: 2m = 200cm, so 200cm = 200cm

Step 2: 1m 75cm vs 180cm

Convert 1m 75cm to cm: 1m 75cm = 175cm, so 175cm < 180cm

Step 3: 3m 50cm vs 3m 45cm

Both in same format, compare centimeters: 50cm > 45cm, so 3m 50cm > 3m 45cm

2m = 200cm
1m 75cm < 180cm
3m 50cm > 3m 45cm
Final answer:

2m = 200cm, 1m 75cm < 180cm, 3m 50cm > 3m 45cm

Applied rules:

• Unit conversion: Convert to same unit before comparing

• Comparison: Compare numbers directly once in same unit

• Symbol selection: Choose appropriate comparison symbol

5 Ordering worksheet
Exercise 5
Order these from shortest to longest: 1m 25cm, 98cm, 1m 5cm, 102cm, 1m 10cm
Definition:

Ordering: Arranging measurements from smallest to largest

Conversion: Convert mixed units to single unit for comparison

1 meter = 100 centimeters

Converting all to centimeters:

1m 25cm = 125cm

98cm = 98cm

1m 5cm = 105cm

102cm = 102cm

1m 10cm = 110cm

Step 1: Convert all to centimeters

1m 25cm = 125cm, 98cm = 98cm, 1m 5cm = 105cm, 102cm = 102cm, 1m 10cm = 110cm

Step 2: Order numbers from smallest to largest

98, 102, 105, 110, 125

Step 3: Match back to original measurements

98cm, 102cm, 1m 5cm, 1m 10cm, 1m 25cm

98cm < 102cm < 1m 5cm < 1m 10cm < 1m 25cm
Final answer:

From shortest to longest: 98cm, 102cm, 1m 5cm, 1m 10cm, 1m 25cm

Applied rules:

• Unit conversion: Convert all measurements to the same unit

• Ordering: Arrange numbers from smallest to largest

• Verification: Check that each next item is longer than the previous

Complete Summary: Comparing Lengths Year 3 Worksheets
Key Concepts and Definitions

Length: The measurement of how long something is from one end to the other.

Standard Units: Consistent ways to measure length that everyone understands.

Centimeter (cm): A small unit of length. About the width of your pinky finger.

Meter (m): A larger unit of length. About the height of a doorknob.

Unit Conversion: Changing measurements from one unit to another (1m = 100cm).

Mixed Units: Measurements that include both meters and centimeters (e.g., 2m 50cm).

Worksheet: A practice sheet containing various problems to solve and practice.

Core Rules and Principles

Rule 1: Always convert measurements to the same unit before comparing, adding, or subtracting.

Rule 2: 1 meter equals exactly 100 centimeters (1m = 100cm).

Rule 3: When adding lengths, add like units (m with m, cm with cm).

Rule 4: When subtracting lengths, borrow from meters if needed (1m = 100cm).

Rule 5: Use comparison symbols: > (greater than), < (less than), = (equal to).

Rule 6: If centimeters add up to 100 or more, convert to meters (100cm = 1m).

Step-by-Step Methods

Method 1 - Unit Conversion:

  1. To convert meters to centimeters: multiply by 100
  2. To convert centimeters to meters: divide by 100
  3. For mixed units: convert meters to centimeters, then add

Method 2 - Addition Problems:

  1. Convert all measurements to the same unit
  2. Add like units (m with m, cm with cm)
  3. If cm total ≥ 100, convert excess to meters
  4. Combine the results

Method 3 - Subtraction Problems:

  1. Ensure both measurements are in the same unit
  2. If needed, borrow from meters (1m = 100cm)
  3. Subtract like units
  4. State the answer in simplest form

Method 4 - Comparison Problems:

  1. Convert both measurements to the same unit
  2. Compare the numbers directly
  3. Insert the appropriate symbol (> < =)
Examples: Simple to Advanced

Simple Example: 1m = 100cm

Moderate Example: 2m 50cm = 250cm

Advanced Example: 3m 20cm + 1m 90cm = 4m 110cm = 5m 10cm

Comparison Example: 1m 50cm vs 145cm → 150cm vs 145cm → 150cm > 145cm

Tips, Tricks, and Common Pitfalls

Tips:

  • Always convert to the same unit before any operation
  • Remember: 1 meter = 100 centimeters
  • When subtracting, borrow from meters if needed (1m = 100cm)
  • Check your answer by doing the reverse operation
  • For ordering, convert all to the same unit first

Common Mistakes:

  • Forgetting to convert units before comparing
  • Adding meters to centimeters directly
  • Not borrowing correctly when subtracting
  • Forgetting that 100cm = 1m
  • Mixing up comparison symbols
Key Notes for Memorization

Memory Aid: "Big Meters, Small Centimeters" - 1 big meter equals 100 small centimeters.

Symbol Trick: The < symbol points to the smaller number.

Process Reminder: Always convert first, then perform the operation.

Verification: After solving, check if your answer makes logical sense.

Worksheet Strategy: Read the problem carefully, identify the operation needed, convert units if necessary, then solve.

Questions & Answers

Question: I often get confused when I have to subtract measurements like 3m - 1m 50cm. How do I handle this?

Answer: This is a common challenge! Here's the step-by-step approach:

  1. Look at the centimeters: you need to subtract 50cm from 0cm (since 3m = 3m 0cm)
  2. You can't subtract 50 from 0, so you need to borrow
  3. Borrow 1 meter from the 3 meters, converting it to 100 centimeters
  4. Now you have 2m 100cm - 1m 50cm = 1m 50cm

Think of it like money: if you have $3.00 and need to spend $1.50, you can't take 50 cents from 0 cents, so you change $1 bill into 100 cents first.

Question: My child finds ordering measurements difficult. How can I help them practice this skill?

Answer: Ordering measurements is a crucial skill! Here's a helpful approach:

  • Start with conversion: Have your child convert all measurements to the same unit (usually centimeters)
  • Write them out: List all converted measurements in order
  • Use a number line: Visualize the numbers on a line to see their relationship
  • Practice with real objects: Measure household items and order them by length

Create fun activities: measure different objects around the house, record their lengths, and arrange them from shortest to longest.

Question: When I add lengths like 2m 50cm + 1m 75cm, I get confused with the answer. How do I do this correctly?

Answer: This is a great question! Here's the correct method:

  1. Add the meters: 2m + 1m = 3m
  2. Add the centimeters: 50cm + 75cm = 125cm
  3. Since 125cm ≥ 100cm, convert: 125cm = 1m 25cm
  4. Add this to the meters: 3m + 1m 25cm = 4m 25cm

Remember: whenever centimeters add up to 100 or more, convert the extra to meters (100cm = 1m).

Think of it like eggs: 125 eggs = 1 dozen (12) and 13 extra eggs, but since we use 100 as our base, 125cm = 1m 25cm.