Answer:
3³
Explanation:
You want an expression using an exponent to represent the number 3·3·3.
Repeated multiplication
As you know, a coefficient is used to represent repeated addition:
a + a + a = 3a
The coefficient 3 in the above expression signifies that 'a' appears in the sum 3 times.
Likewise, repeated multiplication can be represented using a specific notation. An exponent signifies the number of times a factor appears in a product:
a · a · a = a³ . . . . . 'a' is a factor 3 times
Application
You have a sequence of numbers of telephone calls:
3 the first day
3·3 the second day
3·3·3 the third day
The calls on the third day can be represented using an exponent:
3³
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Additional comment
When superscript formatting is not available for the exponent, it is signified by a caret (^). The same number is 3^3 when written in plain text.
As you might expect, a plain text exponent must be enclosed in parentheses if it is other than a single letter or number.