Many of the functions in the 10BA Professional Financial Calculator takes more then one number as input; for instance, the calendar function [ΔDYS] that calculates the number of days between two dates understandably takes two numbers as input: the first number as date1, and the second number as date2. Another common example is the percent change function [%CHG] that calculates the change in percentage between two numbers. Something like the percent of change from 10 to 15 is 50%.
Traditional keystrokes v. Inline function format
To calculate the percent of change from 1250 to 1600 the keystrokes are traditionally like below, which gives 28% as answer.
1250 [INPUT] 1600 [%CHG]
In addition to doing it like the above, any two- or three-number function can also be calculated using the inline format without using [INPUT] as follows.
1250 [%CHG] 1600 [=]
To calculate the number of days between 29 January 2025 and 14 August 2025 (if using the month-day-year format they are January 29 2025 and August 14 2025) you can either use the traditional keystrokes using the [INPUT] key like below.
29.012025 [INPUT] 14.082025 [ΔDAYS]
and the keystrokes using the inline format without the [INPUT] key are like below.
29.012025 [ΔDAYS] 14.082025 [=]
The answer is 197 days. (Note if you use the month-day-year format, the above dates are to be entered as 1.292025 and 8.142025).
So which one to use?
An advantage of using the inline format is input validation. In the above inline keystrokes, as soon as you tap [ΔDAYS] the calculator will check and make sure that the first number that you type is a valid date. If you incidentally type 29.292025 [ΔDAYS] the calculator will immediately display an error and not let you proceed.
Compared this with the traditional keystrokes 29.292025 [INPUT] 14.2025 [ΔDAYS] where it initially accepts the two numbers without complaining and display the error message only after you tap [ΔDAYS] . This is because at first it does not know what you want to do with 29.292025 [INPUT] 14.2025. Only after you tap [ΔDAYS] it knows that you want to do a calendar function and it must check the validity of the two numbers.
However, many people like the traditional keystrokes because they like using the [INPUT] key to clearly separate the numbers. So which keystrokes you want to use is a matter of preference.