Writing Expressions
When verbal statements communicate how quantities are related to each other, they can be translated to algebraic expressions. It is helpful to know the common words associated with the four fundamental operations and understand how these verbal phrases translate to mathematical expressions.
When a value is referred to as simply "a number," the value is unknown and should be represented by a variable. It is important to remember that there is no commutative property of subtraction or division. For these operations, the order of the values is indicated in the verbal phrase.
Operation  Algebraic Expression  Verbal Expression 

$+$ 
$a+8$ 

–  $k13$ 

$\times$ 
$3t$ $3 \cdot t$ $3 \times t$ 

$\div$ 
$\frac{x}{5}$ $x \div 5$ 

Tim and Ben work at the same store. Last week, Tim worked 4 hours fewer than twice as many hours as Ben.
Write an algebraic expression that represents the total number of hours that both Tim and Ben worked.
Choose a variable.
The number of hours Tim worked is described in relation to the number of hours Ben worked. So, let $b$ represent the number of hours Ben worked.