Hours/Minutes on Scientific Calculator
 

Could somebody kindly walk me through how exactly to input hours and minutes, on the scientific calculator?
I have the Casio fx-82MS.

For instance, how do I add 1 hour 30 minutes to 42 minutes to give me 2 hours 12 minutes?

Thanks

1:30+0:42=2:12

Type 1 then press ''' (''' is button to the left of HYP and above ENG)
Type 3 and 0 then press ''' again.
This will display 1.5 (decimal form)
Now press SHIFT (left upper most button) and press '''
This should display 1'30'' ( hr and min)

Press + then type 0 then press ''' again.
Type 4 and 2 then press '''
This will display .7 (decimal form)
Press SHIFT then press ''' to display 0'42''(hr and min)
Press =
This should give the answer in decimal form
Press SHIFT then press ''' to view in hr and min.

You may ommit SHIFT ''' to add in decimal form and after the sum is displayed press SHIFT''' to display it in hr and min.

I hope this helps

on an ordinary calculator try this:

lets say you want to add 1:35 and 1:36

substitute the":"with a "0"

so punch in 1035 +1036 you'll get 2071

add 940 you'll get 3011 ,replace the "0" with a ":" again

and get 3:11

hope this helps if you cant find your scifi calculator

nandyg1
cool!

works on any calculator. still using this untill now, nice nandyg1

Thanks guys!

@overview, what does pressing Shift and "' accomplish?
For instance, if I am to follow the steps you mention, I get 2 hours 12 minutes; however, I also arrive at 2 hours 12 minutes, if I don't press Shift and "'
1"30" + 0"42" = 2"12"

Pressing SHIFT and ''' just changes the display from decimal form to hours and minutes...for double checking if you punched in the correct figures(you may skip this if you know for sure that 1.5 is 1'30'').

@nandyg1 that was cool!
what is this called? the 940rule?

@nandyg1: That's excellent! Thanks.

@nandyg1 Is there a limitation

Eg 14:10 and 12:10
It doesn't seem to add up

Maybe its for single digit time situ

Pls verfiy

OC

940 rule
 

The 940 only needs to be added if the sum of the minutes digits is more than 60.

It works out fine for even two or greater digit hours..

14:58 + 12:56

14058 + 12056 = 26114 + 940 = 27054 = 27:54


14:15 + 15:13 = 14015 + 15013 = 29028 = 29:28 (no need to add 940)

However the limitation is that only two figures can be added one at a time. More than that you need to do it in multiple steps.

But, really cool otherwise

Is there an easy way to subtract time?

press the button under the magenta B. so 1⁰30⁰+ 0⁰42⁰

Adding 940 is really a way of saying "take away 60 and add 1000" - where the last two digits represent the minutes and the thousands represent the hours. You can add as many numbers as you like, you just keep adding 940 until the "minutes" drop below 60.

For an easy example 1:50+1:50+1:50+1:50
Would be 1050+1050+1050+1050 = 4200
Add 940 = 5140
Add 940 = 6080
Add 940 = 7020 (7:20)

Although D°M'S" on a scientific calculator is easier!

Crickey!
Never thought about this!

Have one of the old Casios in my bag - it has been a trusty comrade for a long time and needs one AA battery per decade.
However that DMS button was always too clumsy for me, so I used to convert everything to minutes in the coprocessor behind the eyeballs.
I will opt for the option of adding one page up and than doing a +3000-180, +4000-240 or +5000-300 which will have me most likely covered most of the time.

Worth noting this thread was started 10 years ago.

If the point of the original question was to assist with adding up logbook hours then there are numerous free Hours and Minutes calculator apps in the App Store / Google Play you can use which make life much easier.

On a basic calculator I've always converted hours and minutes to minutes to add them.

Divide the answer by 60 to get hours and decimal hours. Note then subtract the total hours, then multiply the remaining answer by 60 to convert it back to minutes. Sometimes you need to round the answer up/down to the nearest minute, but it's near enough for government work.