To calculate the number of seconds in a year, first you would need to break it down. There are 365 days in a year and there are 24 hours in a day. So, if you multiply the number of hours times the number of days, you would have an answer of 8,760 hours. So, there are 8,760 hours in a year. You would know that there are 60 minutes in an hour. So, if you multiply 60 minutes times the 8,760 hours, you would have 525,600 minutes.
So there are 525,600 minutes in a year. Then you would know that there are 60 seconds in a year. So, you would multiply 525,600 times 60 to get the number of seconds in a year. That would be 31,536,000 seconds.