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Numerical expressions consist of numbers and operations. These operations might include addition, subtraction, multiplication, division, or more complex operations. The goal is to simplify the expression to a single numerical value. When dealing with numerical expressions, always follow a clear, step-by-step process, which can help avoid mistakes.

Understanding each part of the expression is important. For example, in the exercise \[ \frac{72-118-42}{-4} \], we have a numerator and a denominator. The numerator is \[ 72-118-42 \] and the denominator is \[ -4 \].

The primary task is to simplify the numerator first by performing the operations step by step before moving on to the division.

Order of operations is crucial when simplifying any expression. It ensures that calculations are performed in the correct sequence. This is often remembered through the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).

Let's apply the order of operations to the numerator of our exercise: \[72 - 118 - 42\]. There are no parentheses or exponents, so we move straight to subtraction, performed from left to right. Calculate \[72 - 118\] first, giving us \[-46\]. Then subtract 42 from \[-46\], resulting in \[-88\].

Once the numerator has been simplified to a single number, we can proceed with the division by the denominator.

Fraction division can often seem intimidating, but it’s simpler when broken down. Dividing a fraction means taking the numerator and dividing it by the denominator. It's key to remember that dividing two negative numbers results in a positive number.

In our exercise, after simplifying the numerator to \[-88\], we divide by the denominator \[-4\]. This can be written as: \[ \frac{-88}{-4} \]

Perform the division: \[ 88 \div 4 = 22 \]

Since dividing two negative numbers gives a positive result, the final answer is \[22\]. Hence, this methodical approach of first simplifying the numerator, then dividing by the denominator, and keeping the sign rules in mind helps in smoothly solving fraction division problems.