This 3rd Grade Math Problem 5+5+5=15 Was Marked Wrong Due To An Absurd Reason

3rd grade maths question2

Elementary school is the most important phase of any child’s life. Sadly, many school teachers unknowingly destroy the unique capabilities of their pupils just because they aren’t well-versed in that subject to understand that different approach. Here is the famous example of a recent 3rd-grade test sheet in which a student got his points deducted for his multiplication problem 5 x 3=15. He interpreted it as 5+5+5 which is completely okay, but the teacher for some reason had taught and maybe believed herself that the latter number in any multiplication needs to be used rather than the first one. This shows the mathematical shortsightedness of the person who is supposed to be teaching this subject.

3rd grade maths question

Now the poor student would get confused because according to the teacher, tweaking “her rules” of maths doesn’t work. The same thing can be seen in the question below as he had to make an array of 4 x 6 = 24 and he again used the same technique of using the first number as a base. The teacher deducted marks again.

This image of the paper was uploaded on Imgur and Reddit where this particular teacher received a lot of flak from the users because of this by-the-book checking method. You can see the thread here. I believe there is nothing worse than insisting a child is wrong when the poor fellow is right.



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  1. by the result, 5×3 and 3×5 look same. But they are mathematically different. probably the teacher ignored the fact that the base cannot be splitted (e.g. 5 Rs bill × 3 = 15 Rs.; 3 Rs. bill x 5 = 15 Rs. are two different facts) so in the question when we are counting sets of 5, how can we split it into 5 sets of 3s?

    1. In mathematics, a binary operation is commutative
      if changing the order of the operands does not change
      the result. This holds for this simple multiplication task. I think it is fair to allow the student to assume this rather than prove it first, at this level at least.

    2. Wind your neck in. It’s eighth grade maths. And the question doesn’t specify counting sets of five. It just asks for a solution using a specific method. Whilst you are mathematically correct in saying there is a difference, there is no stipulation in the question that it has to be solved in a particular manner.

  2. My friend Pankaj, The answer not incorrect in anyway, I am sure your math teacher taught you that 3 times 5 is nothing but 5 times 3. It is Mathematics and not English where you can twist the meaning by changing order. If you limit yourself with the orthodox checking, then I guess one should not be teaching Mathematics.

  3. Stupid Teacher! That’s a donkey trying to teach maths! What the hell! That teacher doesn’t know the basics of math, and is teaching math?! Fire her/him, and contract an engineer!

  4. Grade 3 kids are learning process. Common core emphasizes process. This way as it continues to be one more complex, they have a greater ability to understand as they understand the process.

    In higher Mather, where you can have multiple steps in a single problem… A transposition of numbers will absolutely result in the wrong answer.

  5. 5+5+5 is more efficient (algorithm) as compared to 3+3+3+3+3 in the context of number of instructions sent to the CPU to solve the multiplication problem.

  6. The teacher is absolutely right, on both the answers. Please note that the logic behind is very simple: Ax B is read as A times B. Hence answer to first question is 5 times 3 i.e . 3+3+3+3+3=15. Similarly answer to 2nd question is 4 times 6 I.e. array of 6 columns × 4 rows.
    Let us not try to promote mediocrity by accepting incorrect answers.

    1. She is incorrect as it is also being explained in the questions as: 5 multiplied by the amount 3. Gramitically its explaining to the child to form the answer in the very way in which they did.

    2. It’s a third grade child we are talking about . You read 5 × 3 as 5 times 3 or 6 × 4 as 6 times four . It doesn’t mean that everyone would read it your way . He solved it the way he understood and the answer is correct as well. At a later stage of life when he develops interest in the subject perhaps he would also learn that, multiplication is commutative, but with teachers with your mentality who tend to demotivate students just because they think they are right and others are wrong the child would loose interest in the subject , probably he would even begin to fear it. So I insist you not to promote any more foolishness by justifying the foolishness of the bully teacher.

    3. Rotate the paper and look again then! Same result! Stop make children cry because of narrow seeing everything.

    4. Pancaj kumar sorry but you and thee teacher are both wrong. 5×3=15 5+5+5=15 5×3=5+5+5 sorry but the kid should have been given full marks because 5×3=5+5+5=15 the proof is right there sorry again. That’s mathematics there’s not just one way of doing and answer.

    5. Are you foolish !!!
      What logic are you talking about ?
      5 times 3 is also 3 times 5, and please don’t spread foolishness with your stupid comment.

    6. Sure if they were multiplying matricies of something but for commutitive multiplication both methods are equally correct

    7. As a matter of semantics the questions can be viewed as the first factor is multiplied by the latter e.g. 5 is multiplied by a factor of three

    8. You’re a moron.

      What matters is the fact that the answers is 15 and 24 respectively and that the teacher marked the kid down for coming up with the correct answer but in a different method. In software development, there are multiple ways of achieving the desired outcome; this child is being taught conformity, not creative thinking.

      Your objection isn’t down to mathematics, it’s an objection about linguistics.

    9. Dear,
      Don’t forget that the multiplication is commutative. In addition, we kill the freely thinking and innovation of our kids by this way. It is math problem, not grammar problem.