CorbettMaths Guide: Converting Units of Time

Master time conversions: hours, minutes, seconds, days, weeks, months with detailed exercises and visual aids.

Solved Exercises: Converting Units of Time
1 Converting Hours to Minutes
Exercise 1
Convert 4 hours to minutes.
How many minutes are in 4 hours?
Definition:

Time Conversion: Changing one unit of time to another using known relationships between units.

Conversion Method:
  1. Identify the relationship between units (1 hour = 60 minutes)
  2. Multiply by the conversion factor
  3. Simplify the result
Key Relationships:

• 1 minute = 60 seconds

• 1 hour = 60 minutes

• 1 day = 24 hours

• 1 week = 7 days

Given
4 hours
Conversion
× 60
Result
240 minutes
Step 1: Identify the relationship

We know that 1 hour = 60 minutes

Step 2: Set up the multiplication

4 hours × 60 minutes/hour

Step 3: Calculate

4 × 60 = 240 minutes

Step 4: Verify

Check: 240 ÷ 60 = 4 hours ✓

4 hours = 240 minutes
Final answer:

4 hours equals 240 minutes

Tip: Remember "Big to Small, Multiply" - when converting from larger units to smaller ones, multiply.
Common Mistake: Don't confuse 60 minutes in an hour with 100 - it's not decimal-based!
2 Converting Minutes to Hours
Exercise 2
Convert 180 minutes to hours.
How many hours are in 180 minutes?
Definition:

Division for Conversion: When converting from smaller units to larger ones, divide by the conversion factor.

Given
180 minutes
Conversion
÷ 60
Result
3 hours
Step 1: Identify the relationship

We know that 1 hour = 60 minutes

Step 2: Set up the division

180 minutes ÷ 60 minutes/hour

Step 3: Calculate

180 ÷ 60 = 3 hours

Step 4: Verify

Check: 3 × 60 = 180 minutes ✓

180 minutes = 3 hours
Final answer:

180 minutes equals 3 hours

Applied rules:

• Small to Big, Divide: When converting from smaller units to larger ones, divide

• Verification: Always check by converting back

• Remainders: If division isn't exact, express as mixed number

Tip: Think of it as grouping - how many groups of 60 minutes fit in 180 minutes?
Common Mistake: Forgetting to divide by 60 when going from minutes to hours.
3 Converting Seconds to Minutes
Exercise 3
Convert 240 seconds to minutes.
How many minutes are in 240 seconds?
Definition:

Seconds to Minutes: Since 1 minute = 60 seconds, divide seconds by 60 to get minutes.

Given
240 seconds
Conversion
÷ 60
Result
4 minutes
Step 1: Identify the relationship

We know that 1 minute = 60 seconds

Step 2: Set up the division

240 seconds ÷ 60 seconds/minute

Step 3: Calculate

240 ÷ 60 = 4 minutes

Step 4: Verify

Check: 4 × 60 = 240 seconds ✓

Step 5: Alternative approach

You can also count by 60s: 60, 120, 180, 240 = 4 groups of 60

240 seconds = 4 minutes
Final answer:

240 seconds equals 4 minutes

Applied rules:

• Conversion Factor: Always use the correct factor (60 for minutes ↔ seconds)

• Operation Direction: Divide when going from small to large units

• Verification: Multiply back to check your answer

Tip: Count by 60s to visualize the conversion: 60, 120, 180, 240 = 4 minutes.
Common Mistake: Confusing 60 seconds per minute with 100 - remember base 60 system!
Time Conversion Infographic
⏰ TIME UNITS ⏰
Key Relationships
SECONDS
60
= 1 MINUTE
MINUTES
60
= 1 HOUR
HOURS
24
= 1 DAY
DAYS
7
= 1 WEEK
WEEK
DAY
HOUR
MIN
SEC
Going Up (Bigger Units): Divide by conversion factor
Going Down (Smaller Units): Multiply by conversion factor
Always Verify: Check your answer by converting back
🔄 CONVERSION RULES 🔄
Memory Aids
"Big to Small, Multiply": Hours → Minutes (multiply by 60)
"Small to Big, Divide": Minutes → Hours (divide by 60)
Count by 60s: 60, 120, 180, 240... to visualize conversions
Additional Concepts & Practice
📚 KEY CONCEPTS
Essential Knowledge
Key definitions:

Time Unit: A standardized quantity used to measure duration

Conversion: Changing from one unit to another while keeping the same amount

Base 60 System: Time uses 60 as the base for minutes and seconds (not 10)

Complete methodology:
  1. Identify units: Determine what you're converting from and to
  2. Know the relationship: Remember the conversion factor (60, 24, 7, etc.)
  3. Choose operation: Multiply if going to smaller units, divide if going to larger
  4. Calculate: Perform the math operation
  5. Verify: Check by converting back
Memory Aid: "From Large to Small, Multiply by the Factor"
Practice Pattern: Start with easy conversions like 1 hour to minutes
Visual Help: Draw a number line counting by 60s for seconds to minutes
Formulas to remember:

• Hours to Minutes: multiply by 60

• Minutes to Hours: divide by 60

• Minutes to Seconds: multiply by 60

• Seconds to Minutes: divide by 60

• Days to Hours: multiply by 24

• Hours to Days: divide by 24

💡 PRACTICE TIPS 💡
Success Strategies
Tip 1: Write down the conversion factor before starting: 1 hour = 60 minutes
Tip 2: Use a calculator for large numbers, but understand the concept
Tip 3: Practice with real-life examples: movie length, school day duration
Tip 4: Always check if your answer makes sense (hours should be smaller than minutes)
Extra Practice Problems
Practice Problem 1
Problem A
Convert 3 hours to minutes
Solution:

3 hours × 60 minutes/hour = 180 minutes

Practice Problem 2
Problem B
Convert 300 minutes to hours
Solution:

300 minutes ÷ 60 minutes/hour = 5 hours

Practice Problem 3
Problem C
Convert 420 seconds to minutes
Solution:

420 seconds ÷ 60 seconds/minute = 7 minutes

Practice Problem 4
Problem D
Convert 2 days to hours
Solution:

2 days × 24 hours/day = 48 hours

🎯 SUCCESS CHECKLIST 🎯
Before Submitting Your Answer
Did you identify the correct conversion factor?
Did you use the correct operation (multiply or divide)?
Does your answer make logical sense?
Did you verify by converting back?

Questions & Answers

Question: I'm confused about whether to multiply or divide when converting time. How do I know which one to use?

Answer: Great question! Here's the simple rule:

  • From BIG to SMALL units: MULTIPLY (Hours → Minutes → Seconds)
  • From SMALL to BIG units: DIVIDE (Seconds → Minutes → Hours)

Examples:

  • Convert 2 hours to minutes: 2 × 60 = 120 minutes (big to small, multiply)
  • Convert 120 minutes to hours: 120 ÷ 60 = 2 hours (small to big, divide)

Think of it this way: when going to smaller pieces, you'll have more of them (so multiply). When going to bigger pieces, you'll have fewer of them (so divide).

Question: Why is time measured in 60s instead of 10s like other numbers? It seems confusing!

Answer: That's a fascinating historical question! The ancient Babylonians used a base-60 number system (called sexagesimal) over 4,000 years ago because:

  • 60 has many divisors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
  • This made it easier to divide time into equal parts
  • The tradition continued through history and became standard

While it might seem strange compared to our base-10 system, the divisibility of 60 makes time calculations work well. Just remember: 60 seconds in a minute, 60 minutes in an hour!

Question: My child struggles with time conversion word problems. Any tips for helping them understand?

Answer: Here are effective strategies to help your child:

  • Use real objects: Count by 60s on fingers, use clock faces
  • Create visual aids: Draw circles representing minutes in an hour
  • Make it practical: "How many minutes in 2 school periods?"
  • Start simple: Begin with 1 hour = 60 minutes before moving to complex problems
  • Practice daily: Ask time conversion questions during routine activities

Consistent practice with familiar contexts helps build confidence. Celebrate small wins!