Binary conversion without BIN2DEC

May you be more precise ?
Number is unable to make a difference between
1234567890123451
and
1234567890123453

It will treat both as
1234567890123450

On the other hand, it is able to convert in BIN every integer with 15 digits

So, I don't understand what you wish to get.
If you wish to decipher integers with more than 15 digits, you must use an other tool or you must work with strings and use an AppleScript to decipher these strings.

In fact the Numbers behaviour is a bit more complicated.

In cell B2 I entered :
=1234567890123450+4
In cell B3 I entered :
=1234567890123450+2
In cell B4
I entered :
=B2=B3
which returns TRUE
In C2 and C3, I entered :
=DEC2BIN(B)

As you may see, with two numbers treated as EQUAL by B4, it returns different results.
And,
more funny, the formula
=C2=C3 inserted in C4 returns TRUE 😉 😟

Yvan KOENIG (VALLAURIS, France) jeudi 15 avril 2010 09:47:12

I repeat : Numbers can't make accurate calculations with numbers having more than 15 digits.

I looked in AppleScript and this one fails if we have more than 14 digits.

My advice is that you must look at applications dedicated to scientific calculations (Mathematica for instance).

Yvan KOENIG (VALLAURIS, France) jeudi 15 avril 2010 13:35:05

Converting binary to decimal is an extremely simple procedure. You don't need formulas. If you format the binary cell as numeral system base 2 and the decimal cell as numeral system base 10, a simple equals sign will do it. That'll get you to 52 binary digits.

Fortunately, that does not satisfy the condition that you are to develop a FORMULA to do it for you homework.

If your assignment is to develop a single formula, it will be a very long one. This is something that will require multiple formulas, each looking at a specific digit and multiplying it by the correct power of 2. There are a couple of ways to do that. Then you will sum them all up. Maybe (just maybe) in Excel it could be done in an array formula but we don't have that in Numbers. It could also be done with an Applescript, just like the examples I see for Excel (via Google search) that use Visual Basic.

Converting binary to decimal is also a collection of functions. In this case they divide by two and keep track of the remainder (a zero or one) then you assemble all those zeros and ones into a binary number.

That's all the hints I'll give. I am assuming you covered the mechanics of the conversion in class so this isn't any big news to you.

Is the assignment to design a spreadsheet that will convert from binary to decimal or is it to develop a formula (i.e., all in one cell)? Conversion from one to the other is an iterative process. It is a simple formula repeated multiple times and, to the best of my knowledge, requires either a program or multiple cells in a spreadsheet.

If it has to be done in a single cell in a spreadsheet application, impress you teacher with the equals operation in Numbers. But also do it the hard way if you want to get credit.

A.

That's a wild-looking expression. I have no idea why it's working at all since you indicated that the input is in A2, yet there are no references to A2 in the expression.

If you get close to an answer I'll be glad to give you some tips, but I'm not going to write the expression for you.

Jerry

So, you want us to do your homework for you?

Jerry

If some one is able to build a converter for numbers with more than 15 digits in Numbers or in AppleScript, I'm interested. 😉

Yvan KOENIG (VALLAURIS, France) jeudi 15 avril 2010 16:36:11