____ is a factor of every number.
1
Idea: A factor of a number is a number that divides it with no remainder.
Let the number be \(n\) (where \(n\) is any whole number like 2, 5, 13, etc.).
Check with multiplication:
\(1 \times n = n\)
This shows 1 “fits into” \(n\) exactly.
Check with division:
\(n \div 1 = n\)
Remainder \(= 0\)
So, 1 divides every number exactly.
Quick examples:
\(4 \div 1 = 4\)
\(9 \div 1 = 9\)
\(25 \div 1 = 25\)
All have remainder \(0\).
Note: We never divide by 0, so 0 cannot be a factor.
Conclusion: Therefore, 1 is a factor of every number.