5th Grade Math Question of the Day

1. $n + 4n = 125$ (correct answer)
2. $4n - n = 125$
3. $n + 4 = 125$
4. $4n + 4 = 125$

Explanation: When you see word problems involving "times as many," you need to carefully translate the relationships into mathematical expressions. This question tests your ability to set up equations from word relationships. Let's break down what we know: there are $n$ non-fiction books, and the library has "4 times as many fiction books as non-fiction books." This means the number of fiction books equals $4n$. Since the total is 125 books, you add the non-fiction books ($n$) plus the fiction books ($4n$) to get: $n + 4n = 125$. This gives us answer choice A. Looking at the wrong answers: Choice B ($4n - n = 125$) incorrectly subtracts the non-fiction books from the fiction books instead of adding them together for the total. Choice C ($n + 4 = 125$) misinterprets "4 times as many" as simply adding 4, rather than multiplying by 4. Choice D ($4n + 4 = 125$) adds an extra 4 that doesn't correspond to anything in the problem. The key strategy here is to identify what each variable represents, then carefully translate "times as many" language. When you see "A has X times as many as B," the amount of A equals X times the amount of B. Always double-check that your equation accounts for all parts mentioned in the problem - in this case, both types of books must add up to the total.