What is used to indicate multiplication when numbers are closely spaced?

When numbers are closely spaced, parentheses are commonly used to indicate multiplication to avoid confusion. This practice helps clarify mathematical expressions, especially in contexts where multiple operations might be present or when numbers appear adjacent to each other. For instance, writing (3)(4) clearly communicates that the two numbers are to be multiplied together, in contrast to simply placing them next to each other without any indication of multiplication.

Brackets are typically used in more complex expressions involving nested operations, while colons and commas do not convey multiplication in mathematical notation. Therefore, the use of parentheses is vital for maintaining clarity in mathematical operations involving multiplication when numbers are closely spaced.