Grade 3 - Mathematics
Topic: Converting Units of Time
Name: _________________________
Date: _________________________
Score: _________________________
Remember: 1 hour = 60 minutes, 1 minute = 60 seconds
Rule: Big to Small = Multiply, Small to Big = Divide
Check: Always verify your answers by converting back!
How many minutes are in 3 hours?
- Identify the relationship: 1 hour = 60 minutes
- Multiply by the conversion factor
- Calculate: 3 × 60 = 180 minutes
- Verify: 180 ÷ 60 = 3 hours ✓
How many hours are in 240 minutes?
- Identify the relationship: 1 hour = 60 minutes
- Divide by the conversion factor
- Calculate: 240 ÷ 60 = 4 hours
- Verify: 4 × 60 = 240 minutes ✓
How many minutes are in 360 seconds?
- Identify the relationship: 1 minute = 60 seconds
- Divide by the conversion factor
- Calculate: 360 ÷ 60 = 6 minutes
- Verify: 6 × 60 = 360 seconds ✓
Convert Hours to Minutes
1. 2 hours = _______ minutes
2. 5 hours = _______ minutes
3. 4 hours = _______ minutes
4. 6 hours = _______ minutes
5. 3 hours = _______ minutes
Convert Minutes to Hours
6. 120 minutes = _______ hours
7. 300 minutes = _______ hours
8. 180 minutes = _______ hours
9. 240 minutes = _______ hours
10. 60 minutes = _______ hours
Convert Seconds to Minutes
11. 120 seconds = _______ minutes
12. 300 seconds = _______ minutes
13. 180 seconds = _______ minutes
14. 240 seconds = _______ minutes
15. 60 seconds = _______ minutes
Time Unit: A standardized quantity used to measure duration (seconds, minutes, hours, days)
Conversion: Changing from one unit to another while keeping the same amount of time
Base 60 System: Time uses 60 as the base for minutes and seconds (not 10 like other measurements)
Relationship: A connection between two quantities that shows how they relate to each other
Factor: A number that divides another number evenly
Multiplication: The operation of repeated addition
Division: The operation of splitting into equal groups
• Big to Small: Multiply by the conversion factor (Hours → Minutes → Seconds)
• Small to Big: Divide by the conversion factor (Seconds → Minutes → Hours)
• Verification: Always check your answer by converting back to the original unit
• Relationships: 1 minute = 60 seconds, 1 hour = 60 minutes, 1 day = 24 hours
• Direction Matters: The operation depends on whether you're going from big to small or small to big
Basic Conversions:
- Identify: Determine what units you're converting from and to
- Recall: Remember the conversion factor (60, 24, 7, etc.)
- Decide: Choose multiply or divide based on direction (big→small: multiply, small→big: divide)
- Calculate: Perform the mathematical operation carefully
- Verify: Check by converting back to ensure accuracy
Simple Examples (Single Step):
- 1 hour = 60 minutes (1 × 60 = 60)
- 2 minutes = 120 seconds (2 × 60 = 120)
- 120 minutes = 2 hours (120 ÷ 60 = 2)
- 180 seconds = 3 minutes (180 ÷ 60 = 3)
Intermediate Examples (Multi-step):
- 3 hours = 180 minutes (3 × 60 = 180)
- 240 minutes = 4 hours (240 ÷ 60 = 4)
- 360 seconds = 6 minutes (360 ÷ 60 = 6)
- 4 hours = 240 minutes (4 × 60 = 240)
Advanced Examples (Word Problems):
- If a movie is 2 hours long, how many minutes is that? (2 × 60 = 120 minutes)
- If you have 300 minutes, how many hours is that? (300 ÷ 60 = 5 hours)
- How many seconds are in 5 minutes? (5 × 60 = 300 seconds)
Challenge Problems
Challenge 1: Sarah practiced piano for 2 hours and 30 minutes on Monday and 1 hour and 45 minutes on Tuesday. How many minutes did she practice in total?
Solution: Monday: (2 × 60) + 30 = 150 minutes; Tuesday: (1 × 60) + 45 = 105 minutes; Total: 150 + 105 = 255 minutes
Challenge 2: A movie starts at 2:15 PM and ends at 4:40 PM. How long is the movie in minutes?
Solution: From 2:15 PM to 4:15 PM = 2 hours = 120 minutes; Plus 25 more minutes = 145 minutes
Questions & Answers
Question: How can I effectively use this worksheet in my classroom?
Answer: Here are effective strategies for using this worksheet:
- Introduction: Review the key concepts and examples as a class
- Guided Practice: Work through the first few problems together
- Independent Work: Allow students to complete the rest individually
- Peer Review: Have students check each other's work
- Assessment: Use the answer key to check understanding
- Extension: Challenge advanced students with word problems
The worksheet includes a complete learning summary for review and reference.
Question: How can I help my child work through this worksheet at home?
Answer: Here are helpful strategies:
- Review Concepts: Go through the definitions and rules together
- Start Simple: Begin with easier problems to build confidence
- Use Visuals: Draw number lines or use manipulatives
- Check Answers: Verify each answer before moving to the next
- Relate to Life: Connect problems to real-world situations
- Be Patient: Allow time for understanding and practice
The complete learning summary provides additional support for review.
Question: Why do we use 60 for time instead of 10 like other numbers? It seems confusing!
Answer: Great question! Ancient people used 60 because:
- 60 can be divided evenly by many numbers: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
- This made sharing time easier in ancient times
- The tradition continued for thousands of years
Think of it like pizza slices - 60 slices can be shared equally among many different group sizes, which is very convenient for time!