Tricky Test 2 Level 32
📝 Walkthrough
Overview
This level displays the math expression "7+7÷7+7×7-7=?" with six answer buttons: 0, 8, 50, 56, 65, 68. The puzzle tests your understanding of order of operations (PEMDAS/BODMAS): division and multiplication are evaluated before addition and subtraction, working left to right within each priority level. The correct answer is 50.
- Difficulty: Regular
- Estimated moves: 1 selection
Step-by-Step Solution
- Read the expression: "7+7÷7+7×7-7=?"
- Apply order of operations: do the division and multiplication first, left to right.
- Compute 7 ÷ 7 = 1.
- Compute 7 × 7 = 49.
- Now substitute back: 7 + 1 + 49 - 7.
- Add/subtract left to right: 7 + 1 = 8; 8 + 49 = 57; 57 - 7 = 50.
- Tap the "50" answer button to submit.
Strategy & Reasoning
The trap is evaluating the expression strictly left-to-right, which would give the wrong answer. By following the standard order of operations, division and multiplication are performed before addition and subtraction. The division 7÷7=1 and multiplication 7×7=49 are computed first, then the additions and subtraction are combined: 7 + 1 + 49 - 7 = 50. The other options (0, 8, 56, 65, 68) represent common arithmetic errors such as ignoring precedence, miscalculating the multiplication, or forgetting the final subtraction.
Tips & Common Mistakes
- Mistake: evaluating left-to-right: ((7+7)÷(7+7)×7)-7 etc. Correct: do division and multiplication first.
- Mistake: forgetting to subtract the final 7. Correct: the expression ends with -7, so the result is 50, not 57.
- Mistake: picking 56 or 65 from rough mental math. Correct: compute exactly — 7 + 1 + 49 - 7 = 50.
- Mistake: mixing up the order of the + and - operations. Correct: after computing the division and multiplication, combine 7 + 1 + 49 - 7 = 50.
The reason left-to-right evaluation fails is that division and multiplication take precedence over addition and subtraction. Computing 7÷7=1 and 7×7=49 first, then combining 7+1+49-7, yields 50. The other options correspond to common errors: skipping the final subtraction gives 57, mis-multiplying gives 56, and sloppy left-to-right grouping gives various wrong totals. Sticking to standard precedence resolves it cleanly.
The key takeaway is to respect order of operations: division and multiplication first, then addition and subtraction. Computing 7÷7=1 and 7×7=49, then combining 7+1+49-7, gives 50. Left-to-right evaluation is the common trap to avoid. Work through each operation deliberately and combine the results carefully to reach the final answer.
In summary, compute division and multiplication first (7÷7=1, 7×7=49), then combine: 7+1+49-7=50, and select the 50 answer button. Working left-to-right without respecting precedence would give a wrong result, so always handle the division and multiplication before the additions and subtraction. Double-check each intermediate calculation before submitting the final answer, and avoid the common mistake of forgetting the final subtraction. The answer button labeled 50 is the correct choice, and the other options represent common arithmetic errors.