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'Mystery number' question in daughter's math homework leaves dad and other grown-ups stumped

Unable to solve the question, the dad shared a photo of it on Reddit and asked for suggestions.

For some people, math problems can be an exhilarating challenge, but for others, they can be downright unnerving. For this dad, who goes by u/eastsideflaco on Reddit, a riddle in the math worksheet of his daughter's homework made him almost 'lose his mind' due to its complexity.

Sharing the homework puzzle in the r/daddit community, the dad pleaded, "So yeah, my daughter said she needed help with her homework and this mystery number crap is about to make me lose it." He also uploaded a picture of the worksheet and asked for a little help.

The question that left the dad stumped read, "Mr. Ruis gives his class clues about a 6-digit mystery number. The 3 is in a place that is 10 times greater than the place of the 0. The 1 is in a place that is 10 times less than the place of the 0. The 4 is in a place that is 10 times more than the place of the 3. The 9 is in a place that is 100 times less than the 1. The 2 is in a place that is 10 times more than the 9. What is Mr. Ruis' 6-digit mystery number?"

Eager to crack the code, Redditors jumped in with their solutions, and most converged on the same answer: 430129. u/gmazz was one of the first users to answer. Others followed. Replying to u/gmazz, u/adutchexpression commented, “That sounds pretty logical," and u/glittered_skunk added, “Telecom engineer and got the same answer.” Some also provided step-by-step method of how they got the right answer.

The mystery number is a 6-digit code, and by applying the principles of place value, we can determine that 430129 is the correct solution. The key is that the 3 occupies a place 10 times greater than the 0, so it falls to the left of the 0 in the number (30). Next, 1 comes at a place 10 times less than 0, which means 1 comes on the right side of 0 (301). Since 4 comes on the place 10 times the place of 3, 4 comes on the left of 3 (4301). Similarly, since 9 comes in place 100 times less than 1, therefore, 9 comes on the extreme right of 1 (4301X9). Finally, 2 is in the place that is 10 times more than 9, which indicates that 2 comes on the left of 9. Hence, the answer is 430129.

Tons of Redditors dropped the right answers in the comments section. Others expressed their opinions about the math worksheet in question. u/realistic-safety-565 said, “It's not math, it's string manipulation. The characters just happen to be digits.” u/-rba- commented, “It's actually a really good way to get kids to understand the concept of what the positions in a number mean. Much more conceptual than the arithmetic most of us learned in grade school, which means it might feel harder but will end up with better actual understanding.”

u/stalwartlight quipped, “They gave her a zebra puzzle for math homework? That's messed up. This is just the math version of Albert Einstein's riddle.” Several said that this particular question comes under the category of “common core math,” which is good for instilling a solid understanding of mathematical fundamentals in children’s brains.

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