555

Do you mean the number 555 itself, or are you asking about a calculation involving 5, 5, and 5? Here are quick possibilities in case you just want a reference:

• 5 + 5 + 5 = 15
• 5 × 5 × 5 = 125
• 5^5 = 3125
• 555 in Roman numerals = DLV
• 555 in hex = 0x22B
• 555 in binary = 1000101011
• Prime factorization of 555 = 3 × 5 × 37

If you’re thinking of something else (e.g., the 555 timer IC, a probability problem, or a specific exam question), tell me the context and I’ll tailor the help.