Simple encoding

Text:

Valid ISBN

Checks ISBN-10 and ISBN-13 (EAN-13)

Usage: Just enter ISBN in box and validation image will pop up.
Be sure whether you want to check 10 digits or 13 digits.

False negative or false positive
Don't take this seriously it may fail at some point. I'll do my best to fix it.
I recommend you don't use it for prefix 979 just for 978
There's is ISBN.org/isbn_converter
or some other site that does what you need.

ISBN

Interest rate

def interest_rate(cost,percent,years):
  return cost * percent ** years

def interest_rate(cost, percent, years):

    rate = percent / 100

    return cost * (1 + rate) ** years

How to change default CD/DVD icon to something else

Steps:

1. Create inf file named „autorun“ with extension „inf“ (autorun.inf)
2. Make an icon file in your favorite Image Manipulation Program (for example: GIMP). Name it whatever you like (later you'll use filename and extension of file)
3. Open autorun.inf file in some text processing program
4. On first line write „[autorun]“ without quotes then press enter.

On second line write this „ICON=here_goes_name_of_the_icon.ico„ again without quotes.

5. Save the autorun.inf file
6. Copy autorun.inf file and the icon file you've made on CD or DVD (must be in „root“ folder)
7. Copy other files you want to CD or DVD
8. Burn DVD or CD
9. Test CD or DVD by „re-injecting“.

That should be it. When you insert CD/DVD and when computer is done reading them icon should appear instead of default CD/DVD icon. I tested this method on Windows XP. When you download icon from web sites default name of icon is usually „favicon.ico“. Standard sizes are (I think) are 16x16 pixels, 32x32px, 64x64px... You might make custom sizes (I didn't tried this one).

Tip: You can hide autorun.inf and favicon.ico

Here's an example.
https://www.mediafire.com/file/dskn5k8yqjj8m2g/autorun.zip/filehttps://www.mediafire.com/file/dskn5k8yqjj8m2g/autorun.zip/fi

Happy Computing!

UPDATE (8.10.2019) - I just found out that it's not INI file but INF
I am sorry for any inconvenience that this misinformation may have caused.
https://www.instructables.com/id/How-to-add-custom-icon-and-long-name-to-your-CDDVD/

Example digits „1301“ could be following:

1. PIN (Computer, Phone, Game, TV, ATM, Locker, KeyLock ...)
2. Year (Chinese, ...)
3. Hours and Minutes
4. Day and Month
5. Phone number (Services, ...)
6. Number of letter (0 - [Space], A - 1, B – 2, C – 3, ...)
7. Lipstik (Leet Speak)
8. Number (Hex, Dec, Oct ...)
9. Part of registration plates
10. Reversed or scrambled
11. Combination any of these above
12. Random digits
13. Something else

FireFox Keyboard Shortcuts

Firefox:
CTRL + SHIFT + P (Private Browsing)
CTRL + T (New Tab)
CTRL + ALT (Switch between tabs)
CTRL + W (Close Tab)
CTRL + H (Show/Hide History)
CTRL + U (View Source) [19.10.2023]
CTRL + I (Page Info) [18.12.2023]
CTRL + J (Shows downloads)
CTRL + F or F3 - Find/Find next
F5 (Refresh webpage)
F11 - Full Screen Mode/Exit Full Screen Mode
ALT + Left Arrow - Page Back (12.09.2020)
ALT + Right Arrow - Page Forward (12.09.2020)
ALT, f, x (EXIT)

Word Keyboard Shortcuts

Word:

BACKSPACE (deletes character on left from blinking cursor)
DELETE (deletes character on right from blinking cursor)

CTRL + Z (Undo)
CTRL + S (Save)


CTRL + A (Selects everything)
CTRL + C (Copy)
CTRL + V (Paste)
CTRL + X (Cut)

CTRL + F (Find...)

CTRL + B (Bold)
CTRL + I (Italic)
CTRL + U (Underline)

ENTER (New Paragraph)
SHIFT + ENTER (New line)
CTRL + ENTER (Page Break New Page)

HOME (Beginning of line)
END (End of line)

SHIFT + F3 (Switch case)

CTRL + HOME (Anchor goes to Start of document)
CTRL + END (Anchor goes to End of document)

CTRL + Right Arrow (word by word)
CTRL + Left Arrow (word by word)

SHIFT + Up Arrow
SHIFT + Down Arrow

SHIFT + END (Selects all from left to right relative to blinking cursor)
Example: H|ello -->  Hello|

SHIFT + HOME (Selects all from right to left relative to blinking cursor)
Example: Hello what|'s app? --> |Hello what's app?

CTRL + SHIFT + END (Depending on where blinking cursor is selects all from left of to right to end of document)
CTRL + SHIFT + HOME (Depending on where blinking cursor is selects all from right to left till start of document)

PAGE UP (Goes from current page to previous page)
PAGE DOWN (Goes from current page to next page)

Practice, practice, practice...