Apply the order of operations with rational numbers
Numerical expressions with rational numbers—including fractions, decimals, and percent representations—are interpreted through grouping symbols, exponents with whole-number powers, multiplication and division, and addition and subtraction, in that hierarchy and from left to right within the same level. The understanding includes preserving the value of negative quantities and equivalent rational forms, recognizing that grouping changes an expression’s meaning, and evaluating nested expressions accurately; symbolic variables, variable exponents, and more advanced exponent rules are outside this scope.
Detailed Explanation: Apply the order of operations with rational numbers
Use this order:
Grouping symbols: parentheses, brackets, or braces
Exponents with whole-number powers
Multiplication and division, from left to right
Addition and subtraction, from left to right
You can rewrite decimals and percents as fractions when that makes the work easier. Be careful to keep negative signs attached to their numbers.
Evaluate:
43−(2(0.5−25%)2÷(−21))
Step 1: Rewrite equivalent rational forms.
0.5=21and25%=10025=41
So the expression becomes
43−(2(21−41)2÷(−21))
Step 2: Evaluate the innermost grouping.
21−41=41
Now we have
43−(2(41)2÷(−21))
Step 3: Evaluate the exponent.
(41)2=161
Now we have
43−(2⋅161÷(−21))
Step 4: Multiply and divide from left to right.
2⋅161=81
Dividing by a negative fraction gives a negative result:
81÷(−21)=81⋅(−2)=−41
So the expression is now
43−(−41)
Step 5: Subtract the negative.
43−(−41)=43+41=1
Therefore,
1
Keep the grouping symbols in mind: changing them can change the value of the expression.
Learn by doing: Apply the order of operations with rational numbers
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Practice:
Algebraic Function Variable Substitution - Fractional Terms (Negatives)