# add 2-digit bit BCD numbers

Discussion in 'Programmer's Corner' started by help_please, Feb 19, 2012.

1. ### help_please Thread Starter New Member

Feb 18, 2012
6
0
I believe I have this working correctly but am not positive what happens once you hit 100, do you have another carry to add to the ones place?

For example:

Is 57 + 57 suppose to equal 115?
99 + 99 = 199?
99 + 1 = 101?
99 + 2 = 102?

Yet 17 + 59 = 76?

Just want to make sure I'm doing this right!!

Last edited: Feb 19, 2012

Oct 2, 2009
12,636
3,454
No.

57 + 57 = 14

99 + 99 = 98

99 + 1 = 00

99 + 2 = 01

3. ### help_please Thread Starter New Member

Feb 18, 2012
6
0
Humm ok

Well I'm displaying 3 digits so it would display hundreds digit.
I was just a little confused as if the carry would carry again.

So is it basically just straight up addition?

4. ### MrChips Moderator

Oct 2, 2009
12,636
3,454
Sorry, you didn't say you were displaying three digits. In that case:

57 + 57 = 114

99 + 99 = 198

99 + 1 = 100

99 + 2 = 101

5. ### help_please Thread Starter New Member

Feb 18, 2012
6
0
That was my fault, sorry! Ok thanks for the help!!