Why can't the answer be 10.43 ?

Question

(15 * 32) / 20 + 45 - 19 =
(480)/20 + 45 - 19
24 + 45 - 19=
69- 19 =
50

Is 10.43 or 50 the correct answer ?

Answer 1

50 is definitely the correct answer.

You would get 10.43 only if you grouped the last three numbers (20 + 45 - 19) and divided by their total. BUT, there are no grouping symbols there, so don't do it!

Answer 2

When parentheses are not shown, multiplications and divisions are done before additions and subtractions. Therefore, the correct order of operations is as you have shown in the problem. You can change this order by enclosing the subexpressions to be done first in parentheses. If you had enclosed the expression 20 + 45 - 19 in parentheses, then you would have done these additions and subtractions before the division, resulting in the fraction 240/23, which evaluates to approximately 10.43.

There are some exceptions to this rule. If the original problem had shown the 15 * 32 on top of a long horizontal divisor bar and the 20 + 45 - 19 on the bottom, there is an implied set of parentheses around the subexpression making up the numerator and another around the subexpression making up the denominator. If the problem was written this way, you must supply the parentheses explicitly when rewriting the expression with another kind of divide symbol, such as the ASCII slash used in this question.

Another such exception occurs when evaluating expressions under a radical (square root) symbol. The entire expression under the radical symbol has an implied set of parentheses around it and must be evaluated before taking the square root. Again, when translating such an expression to a single line, the formerly implied parentheses must be made explicit.

Answer 3

480/20 + 45 - 19
= 24 + 26
= 50

Answer 4

50 is the correct answer. the reason is because you need to do what's in the parentheses first before you can do anything else. if you do 20 + 45 - 19 that equals 46. if you divide 480 by 46 that gives you 10.43. but you must always do parentheses first. weird.

Answer 5

Order of operations.

Parentheses > Multiplication > Division > Addition > Subtraction

Answer 6

50 is the correct answer

Answer 7

your process is correct, so 50 is the answer.

evaluate calcs in the brackets first, then do multiplication/division before addition/subtraction