Writing Algebraic Expressions

Writing Algebraic Expressions CONVENTION We generally write the variable before the number in an addition problem. [ x + 8 ] We generally write the number before the variable in a multiplication problem. [ 8x ]

ADDITION (see convention above) Total [A board is cut into two pieces. One piece has a length of 67 inches. If the other piece has a length of z inches, what was the total length of the board, in inches, before it was cut?  z + 67] Sum [The sum of 8 and w  w + 8] Altogether [ Jolene has w computers upstairs and eight computers downstairs. How many computers does she have altogether?  w + 8] More than*– not the same as IS MORE THAN [8 more than w  w + 8] Added to [8 added to w  w + 8] Increased by [w increased by 8  w + 8] Plus [8 plus w  w + 8]

SUBTRACTION (careful with order) Less than*– not the same as IS LESS THAN [18 less than y  y – 18] Difference [the difference of r and 4  r – 4] Other [If a 53-inch board is cut into two pieces and one piece is x inches, how long is the other piece?  53 - x] Left or left over [In a given month, Jolene earns d dollars and owes $987 in expenses. How much, in dollars, does she have left after paying for expenses?  d – 987] Decreased by [z decreased by 72  z – 72] Subtracted from* [8 subtracted from m  m – 8] Minus [7 minus n  n – 7]

MULTIPLICATION (see convention above) Product [the product of m and 7  7m] Twice [twice z  2z] Of [one-half of x  ½x] Times [three times z  3z] Multiplied by [g multiplied by 4  4g] At/each [y DVDs at $12 each  12y ]

DIVISION (careful with order) Quotient [the quotient of m and 3  m/3 ] Each—careful with “at” and “total” and other addition or multiplication words. (If 6 DVDs cost x dollars total, how much does each DVD cost?  x/6) Per [If Jolene earns y dollars in a year, how much is that per week?  y/52] Ratio [The ratio of n and 7  n/7] Divided by [n divided by 8  n/8] “percent” means “Divided by 100” [ z percent  z/100 ]

PROPORTIONS How many ______are in _____ [How many minutes are there in h hours?  60h] If one ______, how many are _____ [If one notebook costs n dollars, what is the cost, in dollars, of 15 notebooks?  15n]

*CAREFUL WITH ORDER —these words indicate switch the order From Than