My calculator will add, but after my total and then I want to subtract, it subtracts by the number I added.

It probably uses adding machine logic. Try the following example.


3+
4-
5+
*

You should get 3, -1, and 4 on the screen, the running total. The tape should show the +3, -4, +5, and finally 4, the numbers that you entered and the total. Think of each entry as adding/subtracting integers on a number line rather than 3+4-5;)

Let me know if you have any questions.

Paul

Could it be that it has adding machine logic and not calculator logic?

Let's do an experiment. 3+ 3+ 5-. Is the answer 1?

If so, it is working like an adding machine. Every number you enter is considered positive or negative and it keeps a running total.

Let me know if you have any questions.

Good luck.

Paul

SUM means adding not subtracting. so if you were wanting to add the total (the sum) of the amounts of the hundreds and the tens would be 170 plus 130 which would be 300 but the remainder from subtracting 130 from 170 would be 40. That would leave the single units 5 minus 4 of which the remainder is 1. So, the remainder from subtracting 134 from 175 is the reminder of subtracting the one hundred from the one hundred which is zero added to the remainder of subtracting the tens (70 minus 30) which is the remainder of 40 plus the remainder of subtracting the units of 5 minus 4 which is 1. So you need to add the 0 and the 40 and 1 which is the remaining sum of 41.

Moisture damage if exposed to humidity

You can download the manual from
http://downloads.canon.com/cpr/software/calculator/P170-DH-(USA-HWB).pdf

128000 - 10000 then press = or chain the calculation by pressing + or - and the number you want to add or subtract.

use the + key after each number to add the total will appear on screen. When all numbers have been added, enter number to subtract and then press - key. The subtracted number will appear in read on the paper (if two color). and then press the star key to get total.

Hi,

MR is Memory Recall
MC is Memory Clear
M+ is Memory add
M- is Memory subtract

These are used to add and subtract the answers to multi-step equations so you can do the small steps with the calculator, then store, change or recall the total as needed. You might add a long string of numbers in groups this way. Or you can do all operations in one parenthesis, then just store the total of each.

A good problem to illustrate this would be : (123 x 3) + (55 - 24) + (10^2) - (7 x 8) = ???
Using MR, M+ and M-, you can do each one as a group, and only store the answers. 123 x 3 = 369 so M+ to put 369 in memory. Clear it from the calculator. 55 - 24 = 31, so M+ to put this in memory and add to the 369 already there. Clear it from the calculator. 10^2 = 100, so M+ this to memory also to add it. Clear it from the calculator. 7 x 8 = 56 so M- this to SUBTRACT it from memory. Clear it from the calculator if desired. Now, when you then hit MR, you will get the total of all of these small equations in parenthesis -- 444.

Hope i helped you.

Thanks for using ' Fixya ' and have a nice day!!

Big calculators work a little different than handheld calculators. Like the above commentor explained, if you have a basic "whats 100 minus 20?" You have to entered as 100 + 20 -- And when you hit the minus button at the end, it will give you the total. 100 is the positive number, and the 20 is the negative number that your subtracting. Also you can hit 20 -- 100 + and get the same total because you entering 20 as the negative and 100 as the positive, just in reverse.

With an adding machine, which is what this is, you enter the number followed by the + or -. If you wanted to add 10+20, you would enter 10 then + then 20 then +. This would show your answer. If you are using the printer and you wish to see the final answer on the paper, hit the * key and your answer will print.

If you are subtracting, let's say 100-40, you would enter 100 then + then 40 then - then *. Adding machines expect you to enter long strings of numbers to total. You may have both positive and negative numbers. So, you always enter the number first followed by either positive + or negative -.

You might have 100 + 25 - 37 - 1 + 50. For that enter:
100+25+37-1-50+ then *

Different than a calculator but the same for all "adding machines". This machine should really be called an adding machine since that is the kind of input it is looking for.

Because this is an adding machine you would use the total button (*) not the = for ading and subtracting the = is only used in multiplcation and division