What words can you spell out on a calculator?

Answer 1

hi (14), hello (07734), hell (7734), shell (77345), mom or wow (303), sizzle (372215), bolo (0708), Oboe (3080), lie (317), lies (5317), etc.

Answer 2

The simplified "figure 8" layout of LCD and LED displays can make numbers appear as letters when inverted (upside-down)*.
Number-letter pairs (some the same inverted or not)

• The number 0 is "O" (either way)
• The number 1 is "I" (either way)
• The number 5 is "S" (either way)
• The number 3 is "E" (inverted)
• The number 4 is "h" (inverted)
• The number 7 is "L" (inverted)
• The number 9 is "b" (inverted)

So any words that can be spelled with B, E, H, I, L, O, or S can be formed by inverted numbers. Example : the number "710 77345" appears inverted as "Shell Oil".
*This scheme obviously preceded text keyboards on calculators and phone devices.

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If you have a modern scientific calculator, there is no need to turn the screen.
If you have a casio FX83ES, use alpha or shift. look at the buttons and you'll see red and yellow letters. You can also make faces. Here is a list of charcaters you can use:
A B C D e X Y M : ( ) -
Here is one of the things you can do
(-:)
using shift, there are eyeballs, and a flashing arrow used for hair, beards, moustaches, etc.