stepcheck / Skills / Order of operations
Grade 6 · 5.OA.A.1, 6.EE.A.2c
Find the error: order of operations
A find-the-error worksheet for multiply before adding, exponents before everything: 3 + 4 × 6, 20 − 6 + 3, 5 + 3². Each problem shows a student's worked solution with one planted mistake; students find the wrong step, name the misconception and solve it correctly. The answer key is computed, so it is always right.
Mistakes this sheet plants
- Worked left to right, ignoring multiplication first. Multiplication comes before addition: 9 × 5 first.Example: 13 + 9 × 5 − 5 worked to 105 instead of 53.
- Added before subtracting. Addition and subtraction have the same rank: work them from left to right.Example: 33 − 13 + 11 worked to 9 instead of 31.
- Read the exponent as multiplication. 3² means 3 × 3 = 9, not 3 × 2.Example: 11 + 6 × 3² worked to 47 instead of 65.
Related: Adding decimals · Adding fractions with unlike denominators · Long division (zeros in the quotient, remainders) · Multiplying decimals · One-step equations · The distributive property
Each problem was solved by a student, and each has exactly one mistake. Find the step with the mistake, say what went wrong, and solve the problem correctly.
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1 11 + 6 × 3²
Finn's work
- Exponent first: 3² = 3 × 2 = 6.
- Multiply: 6 × 6 = 36.
- Add: 11 + 36 = 47.
Finn's answer: 47
Wrong step: What went wrong: Correct answer:
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2 13 + 9 × 5 − 5
Theo's work
- Work left to right: 13 + 9 = 22.
- 22 × 5 = 110.
- 110 − 5 = 105.
Theo's answer: 105
Wrong step: What went wrong: Correct answer:
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3 33 − 13 + 11
Sam's work
- Add first: 13 + 11 = 24.
- 33 − 24 = 9.
Sam's answer: 9
Wrong step: What went wrong: Correct answer:
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4 17 − 5 + 6
Ana's work
- Add first: 5 + 6 = 11.
- 17 − 11 = 6.
Ana's answer: 6
Wrong step: What went wrong: Correct answer:
| # | Wrong step | The mistake | Correct answer |
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| 1 | Step 1 | Read the exponent as multiplication. 3² means 3 × 3 = 9, not 3 × 2.Correct step 1: Exponent first: 3² = 3 × 3 = 9. | 65not 47 |
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| 2 | Step 1 | Worked left to right, ignoring multiplication first. Multiplication comes before addition: 9 × 5 first.Correct step 1: Multiply first: 9 × 5 = 45. | 53not 105 |
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| 3 | Step 1 | Added before subtracting. Addition and subtraction have the same rank: work them from left to right.Correct step 1: Left to right, subtract first: 33 − 13 = 20. | 31not 9 |
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| 4 | Step 1 | Added before subtracting. Addition and subtraction have the same rank: work them from left to right.Correct step 1: Left to right, subtract first: 17 − 5 = 12. | 18not 6 |
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A sample: open this exact sheet or make one with new numbers.