555

Not sure what you want with 555. Here are a few quick directions—pick one, and I’ll dive in or quiz you.

• Math/number theory: prime factorization (555 = 3 × 5 × 37), divisibility, quick problems.
• Electronics/CS: 555 timer IC basics (astable/monostable modes) with formulas.
• Numeral systems: 555 in Roman numerals (DLV), binary (1000101011), hex (0x22B).
• Quick drills: mental math problems involving 555 (multiplication, etc.).

Tell me which topic you want, or share a specific problem, and I’ll help.