We use units of time to describe how much time something takes or will take.
If we know a time in one unit, like seconds, we can convert it into any other unit of time, like weeks, using conversion factors.
🚶 Here are the steps to follow:
Step 1. Know what unit you are converting from. This is the time measurement that you have.
Step 2. Know what unit you are converting to.
Step 3. Find out the conversion ratio between the units.
Step 4. Multiply or divide depending on what unit is being converted to.
Multiply if converting from a larger time unit to a smaller one.
Divide if converting from a smaller time unit to a larger one.
There are 60 seconds in 1 minute.
The conversion ratio between these two units is 60.
Let's say we want to convert this:
90 minutes = _______ seconds
We're converting from minutes to seconds.
"Minute" is a larger unit than "second".
So we have to multiply.
90 minutes × 60 = 5,400 seconds ✅
Awesome.
Next, can you convert the other way, from seconds to minutes?
7200 seconds = _______ minutes
"Second" is a smaller unit than "minute".
This means we have to divide the number of seconds by 60.
60 is our conversion ratio.
7200 ÷ 60 = ?
After doing the long division, we see that:
7,200 seconds is equal to 120 minutes. ✅
There are 60 minutes in an hour.
The conversion ratio between minutes and hours is 60.
Can you convert 12.5 hours to minutes, using this conversion ratio?
12.5 hours = _______ minutes
Do we divide or multiply?
We're converting from hours to minutes. "Hour" is a larger unit than "minute". We're going to split it up into smaller pieces of time.
This means that we need to multiply.
12.5 × 60 = ?
Using column form, you can figure out that:
12.5 × 60 = 750 minutes ✅
Awesome. You just converted from hours to minutes.
Now, can you convert the other way, from minutes to hours?
1380 minutes = _______ hours
What is our conversion ratio, or factor?
That's right! 60 is our conversion ratio.
We need to divide.
1380 ÷ 60 = 23 hours
Using long division, we can figure out that 1,380 minutes is equal to 23 hours. ✅
Do you remember how many hours are in a day?
Yes, there are 24 hours in 1 day.
24 is the conversion ratio for days to hours.
Let's say we want to know how many hours are in 15 days.
15 days = _______ hours
"Day" is a larger unit than "hour". So we multiply 15 days with our conversion ratio.
15 × 24 = 360 hours ✅
Excellent work.
Now, let's try converting the other way, from hours to days.
960 hours = ____ days.
What should we do?
We divide 960 hours by 24.
960 ÷ 24 = 40 days
960 hours is equal to 40 days. ✅
There are 7 days in a week.
The conversion ratio for weeks to days is 7.
So how many days are there in 14 weeks?
We multiply 14 weeks by 7.
14 × 7 = 98 days
There are 98 days in 14 weeks. ✅
Good job.
Now, how many weeks are in 336 days?
336 days = _______ weeks
What should we do? Multiply or divide?
We divide.
Using long division, we can figure out that:
336 days ÷ 7 = 48 weeks ✅
There are 12 months in one year.
12 is the conversion ratio for year to months.
Let's try converting months to years.
168 months = _______ years
Do we divide or multiply?
Since month is a smaller unit than year, we divide our months by the conversion factor.
168 months ÷ 12 = 14 years
168 months is equal to 14 years. ✅
You've got it. 👏
Let's try another example.
7 years = _______ months
So what should we do?
We multiply 7 years by the conversion ratio.
7 × 12 = 84 months
7 years is equal to 84 months. ✅
Excellent.
Now, it's a perfect time for practice. 😂