Answer:
You could memorize conversions, or use conversion charts, or do a quick internet search for help.
Explanation:
I'll do a few of the conversions for you
Seconds to minutes:
there are 60 seconds in one minute. So if you are wondering how many seconds are in 3 and 1/2 minutes, you would do this conversion:
60 sec/min times x sec/3.5 min
which can be written as 60 x 3.5 = 210. so "x" seconds would be 210 seconds in 3 1/2 minutes.
you could do the same thing in the opposite direction for minutes to seconds:
1 min has 60 seconds. So in 7.25 minutes, how many seconds are there?
1 min/60 sec times 7.25 min/x sec
which can be written as 7.25 x 60 = 435. so "x" seconds would be 435 seconds in 7.25 minutes.
hours to seconds:
this one is slightly more complicated
In one hour there are 60 minutes, and in one minute there are 60 seconds.
so to convert from hours to seconds you would do this conversion:
1 hr/60 min times 1 min/60 sec. then the "min" would cancel out, and you would be left with the label "hr/sec". to do the math, it would be 1 hr / 60 x 60.
60x60 = 3600. so you would have 1 hr/3600 sec. So in one hour there are 3600 seconds.
so if you want to know how many seconds are in 6.75 hours:
6.75 hr/x sec times 3600 sec/1 hr
6.75 x 3600 = 24,300 so there are 24,300 seconds in 6.75 hours.
I hope this helps :)
