First grade math question

Looking for opinions on what the correct answer is for this question on a first grade math test. I’ll post what the answer key says is the correct answer and what I think the correct answer (or at least the most correct answer) should be later.

My answer, based on the picture that went with the question is:

15-5-2

15-5-2
ETA: is this homework? :smiley:

I think that the question isn’t asking what it thinks it’s asking. But near as I can figure out, it’s trying to ask for a description of what’s being done in each step, and so I would bubble in “15 - 5” under the first column (as a description of what that column is doing) as well as “15 - 5 - 2” under the second (as a description of the second step).

Well, then wouldn’t the second step be 10-2, if 15-5 is the first step, unless the question is asking for the final answer under step 2?

I agree it could be read as two choices under step 1 and two choices under step 2 (though I’d expect the choices under step 2 to only describe what’s happening under step 2). Without seeing the directions, it’s hard to know.

It is. It’s 15 – 5 (which is 10) – 2.

I understand the math.

I was suggesting that if you were supposed to choose from the answers below each step, the choices under step two would probably have been 10-2, rather than the three digit choices provided.

There’s something fishy about these questions. You say that it’s a first-grade test. Look at the sentences there:

Which shows how to make a ten to solve 15 - 7?

Which shows the pencils in order from shortest to longest?

Those aren’t first-grade sentences. My offhand estimate is that they’re third-grade sentences. Where did you get this test (or homework or whatever it’s supposed to be)?

Yes, I do say that. It’s a beginning of year first grade assessment.

I don’t mean to be an old guy whining about newfangled teaching methods, but I had a really hard time figuring out what that question was even asking. It just seems like a lot of complexity for a question of simple arithmetic. But, near as I can figure, they seem to want 15-5-2. Why you would ever diagram out the math like that is beyond me.

I also agree with this.

Third graders these days are writing research papers.

Okay, the answer key says the correct answer is 15 - 5 - 2.

I think the best answer is 15 - 5 as that’s the only answer that leaves one with a ten.

The question asks which one shows “how to make a ten.” Yes, that is followed by “to solve 15 - 7”, but it’s still asking how to make a ten, regardless of what follows or what the pictures show.

Oh well, I guess I’m not smarter than a first grader.

The “how to make a ten” is a methodology for approaching math problems. It means doing an intermediate step to get you to 10, and then finishing the problem to get the final answer. It’s based on the idea that working with 10s is easier to comprehend.

My dad taught me this 40 years ago as a shortcut for doing math in my head, when I was little.

Bolding mine. We’re not asked to finish the problem. We’re asked which answer shows how to make a ten. Only one answer does.

My son is a first grader and has been doing this type of math. I like it, because it is how I do quick math in my head and I see its usefulness.

I also agree that the written instructions are often beyond my 1st grader’s reading abilities.

“Making a ten” describes the strategy, not the goal of the question.

You’re asked how to make a 10 to solve 15-7. 15-5 only makes 10. 15-10-2 makes 10 and solves 15-7. The wording may sound clunky, but if you have been taught this method, it should be obvious what is being asked.

He wouldn’t be learning much if they were strictly within his abilities. :slight_smile:

I like these kinds of approaches, and it’s also how my dad taught me to do mental arithmetic when I was little. But when they are curriculum-ized, they start to come with some weird vocabulary (“make a ten”) which can be very frustrating for parents who don’t know WTF the worksheets are talking about, even when the actual math is very simple. Of course, the weird vocabulary is ultimately necessary so the students know what process you’re referring to. It can be frustrating for parents who have never been exposed to it before, especially if the curriculum materials are shoddy, as a lot of them are.

It’s certainly not a sentence a first-grader would write, but it’s one that a first-grader would probably understand. And the question itself couldn’t really be for anything other than first grade: Somewhere around age 4 or 5 is when children begin to understand the concept of “in order”, and so a question like that would be seeking to identify the late bloomers.

x-ray vision writes:

> It’s a beginning of year first grade assessment.

What does that even mean and where does this come from? What is a “year first grade assessment”? How did you get one? Is this something you took from a first-grader or a first-grade teacher? Is it something that you found on the Internet? Is it something that was sent to you as some E-mail spam?