Question

Find and correct the error in the work shown below:

7 + 3 ∙ 8 - 42 ÷ 2 * 10 ∙ 8 - 16 ÷ 2 * 80 - 872

A. The student multiplied 3 by 8 before adding 7. The correct answer should be 23.
B. The student subtracted 8 and 42 before dividing by 2. The correct answer should be 27.
C. The student added 8 and -42 before dividing by 2. The correct answer should be 27.
D. The student added 7 and 3 before multiplying by 8. The correct answer should be 23.

Answer 1

The student made an error by adding 7 and 3 before multiplying by 8. The correct answer is 1448.

Step-by-step explanation:

The error in the given work is that the student added 7 and 3 before multiplying by 8. The correct order of operations is to perform multiplication and division before addition and subtraction. Let's correct the calculation step by step:

1. Multiply 3 by 8: 3 * 8 = 24
2. Divide 42 by 2: 42 / 2 = 21
3. Multiply 10 by 8: 10 * 8 = 80
4. Divide 16 by 2: 16 / 2 = 8
5. Multiply 80 by 21: 80 * 21 = 1680
6. Multiply 8 by 80: 8 * 80 = 640
7. Subtract 872 from the previous result: 640 - 872 = -232
8. Add the previous two results: 1680 + (-232) = 1448

The correct answer is 1448. Therefore, the option D is the correct answer.