Common Mistakes: Multiplication & Division
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Everyone makes mistakes when learning! The best way to get better is to understand WHY mistakes happen and learn how to avoid them.
Mistake #1: Confusing Multiplication and Addition
Wrong: 6 x 4 = 10
This student added 6 + 4 instead of multiplying!
Right: 6 x 4 = 24
Remember: Multiplication means "groups of" - 6 groups of 4 equals 24.
Mistake #2: Mixing Up Similar Facts
Wrong: 6 x 8 = 42
This student confused 6 x 7 = 42 with 6 x 8!
Right: 6 x 8 = 48
Tip: Check by adding one more group. 42 + 6 = 48.
Mistake #3: Division Order Matters
Wrong: 56 / 7 = 7 because 7 / 7 = 1
This student divided the wrong way!
Right: 56 / 7 = 8
Ask: "What times 7 equals 56?" Answer: 8 x 7 = 56.
Practice: Find the Mistake
Can you spot what went wrong?
1. A student wrote: 7 x 5 = 12. What mistake did they make?
A) They added instead of multiplied
B) They subtracted instead of multiplied
C) They divided instead of multiplied
D) They made no mistake
Answer
A) - They added 7 + 5 = 12 instead of multiplying 7 x 5 = 35.
2. A student wrote: 9 x 6 = 56. What is the correct answer?
A) 45
B) 54
C) 63
D) 56 is correct
Answer
B) 54 - The student confused 9 x 6 with 8 x 7 = 56. The correct answer is 54.
3. A student thinks 0 x 8 = 8. What should you tell them?
A) They're correct
B) Zero times any number equals zero
C) They should add instead
D) The answer is 80
Answer
B) - Any number times 0 equals 0. Zero groups of 8 means no items at all!
4. A student wrote: 48 / 6 = 9. Is this correct?
A) Yes, 48 / 6 = 9
B) No, 48 / 6 = 8
C) No, 48 / 6 = 7
D) No, 48 / 6 = 6
Answer
B) No, 48 / 6 = 8 - Check: 6 x 8 = 48. The student was off by one.
5. A student says 4 x 7 and 7 x 4 have different answers. Are they right?
A) Yes, the order changes the answer
B) No, both equal 28
C) Yes, 4 x 7 = 28 but 7 x 4 = 24
D) It depends on the problem
Answer
B) - The commutative property says order doesn't matter in multiplication. Both equal 28.
6. A student wrote: 8 x 8 = 72. What's the correct answer?
A) 64
B) 72
C) 80
D) 56
Answer
A) 64 - 8 x 8 = 64. The student may have confused it with 8 x 9 = 72.
7. Why might someone incorrectly say 1 x 9 = 19?
A) They put the numbers next to each other
B) They multiplied correctly
C) They added correctly
D) There's no pattern to the mistake
Answer
A) - The student may have just put the digits together. Remember: 1 x 9 = 9 because any number times 1 equals itself.
8. A student divided 63 / 9 and got 6. What went wrong?
A) Nothing, 6 is correct
B) They confused it with 54 / 9
C) They added instead
D) They multiplied instead
Answer
B) - They confused the fact. 54 / 9 = 6, but 63 / 9 = 7.
9. What's the best way to check if 7 x 9 = 63 is correct?
A) Just memorize it
B) Divide: 63 / 9 should equal 7
C) Add 7 + 9
D) There's no way to check
Answer
B) - Use the inverse operation! If 7 x 9 = 63, then 63 / 9 should equal 7, and 63 / 7 should equal 9.
10. Which strategy helps avoid mixing up similar facts like 6 x 7 and 6 x 8?
A) Guess and hope
B) Skip those problems
C) Use a fact you know and add or subtract one group
D) Always use a calculator
Answer
C) - If you know 6 x 7 = 42, you can find 6 x 8 by adding one more group of 6: 42 + 6 = 48.
Next Steps
- Always check your work using inverse operations
- When unsure, use a strategy like breaking apart numbers
- Practice the facts you confuse most often
- Continue to the Unit Quiz