The en-dash is used for ranges of values, such as "1994–2010," "pp. 183–652."
I find it fine to use the en-dash in such cases in a presentation.
In some cases, it could be convenient not to express a range of values using the en-dash; for example, the Guide for the Use of the International System of Units suggest not to use the en-dash if it could be confused with a subtraction, such as in "an amperage of 2–5 A."
The value of a quantity is expressed as the product of a number and a unit (see Sec. 7.1). Thus, to avoid possible confusion, this Guide takes the position that values of quantities must be written so that it is completely clear to which unit symbols the numerical values of the quantities belong. Also to avoid possible confusion, this Guide strongly recommends that the word “to” be used to indicate a range of values for a quantity instead of a range dash (that is, a long hyphen) because the dash could be misinterpreted as a minus sign. (The first of these recommendations once again recognizes that unit symbols are not like ordinary words or abbreviations but are mathematical entities—see Sec. 7.2.)—The Guide for the use of the International System of Units, page 18.