Computing in Feet and Inches

[bauerpower]

I am wondering if there are any programs or applications that would allow me to easily add and subtract in feet and inches. I would like to be able to input 6'5"+8'3.25" or similar and have it give an output in feet and inches.

I have a TI-89 Calculator

[luby]

if you have an ti 85 there's this, but as for a 83 goes, I don't think there is one. I would suggest building your own.

[JoostinOnline]

He has an 89, although I think he edited his post after you posted. I don't know if the 89 has one, but Unit Ops works for the TI-83+.

[Weregoose]

The TI-89 has built-in unit conversion. I don't own an 89, but I tried my best with this explanation through research: enter your number, press [2nd] [3], choose "Length" and go right, select the desired unit, and insert the convert symbol with [2nd] [MODE]. Follow it up with the other unit type that you obtain similarly and press enter. I assume you'll only get a decimal, but you can use the above process to get the feet, from which you'll take the integer part to subtract from the original number and then convert the remainder to inches. The result here would be the inches, and the integer part from earlier, the feet. This should work until you get better advice from an 89 expert!

[bauerpower]

I am aware of the unit conversion opperation but am looking for a faster way to input and recieve results.

[Weregoose]

Are there any TI-89 programmers slinking around?

[DarkerLine]

There are, but I don't see any "faster" way than the built-in unit conversion - the most you could do is write a function, which would certainly be slower, and less convenient as well.

How would this work?

Define toFtInch(num)={floor(num/12),mod(num,12)}
Define footInch(foot,inch)=12*foot+inch

To do the math, you would use footInch to enter a value in feet and inches, and toFtInch to split it up. For example, 6'5"+8'3.25" would be done as follows:

toFtInch(footInch(6,5)+footInch(8,3.25))

You will get back {14 8.25} which stands for 14'8.25".

Alternatively, through a lengthy and tedious string parsing process, you could write a program that will be able to deal with an expression entered as 6'5"+8'3.25" directly, and return the answer in the same format. It seems to me to be overkill, though.