The problem with that style, at least on this message board, is that it looks like 1 minus 1/3.
(AP Style advocates for a space. I believe Chicago Manual of Style wants a hyphen.)
Assume you have a standard 2 kg bag of sugar. How, exactly, would you go about it to measure up 1 1/3 kg?
(You have a digital scale, and all other common kitchen utensils at your disposal.)
And *that’s *why the “1 1/3” notation is useless.
Then complain as loudly as you can. If it’s optional for the teacher, then complain to their head of department or the head of the school. If it’s prescribed from on high, it looks like a systemic problem, so go straight to the top. Whoever’s responsible is not doing the job they’re paid for.
I could not for the life of me even guess what you’re getting at with that question. 1 1/3 is a unit plus another third. It’s a concept that’s been in use of centuries and still is – look up any online recipe. I have a brand new measuring cup that has metric measures on one side and imperial (cups) on the other. If I want 1 1/3 cups of something I fill it up past the “1 cup” mark up to the “1/3” mark above it. How is this a problem?
Fractions and decimal notation have their respective uses in different contexts. Digital displays don’t do fractions, but humans estimating quantities find fractions very useful. It’s why fractions are so pervasive in recipes. You are imagining some kind of non-existent problem.
It’s hard to withhold a certain admiration for whoever wrote this question: no ordinary level of sloppiness could possibly have produced something this bad.
I think the most rational response would be to refuse to answer, on the basis that the question is not clearly distinguishable from gibberish.
I would use a scale graduated in 1/3 kgs …
ETA: I think judging an entire course curricula based on one question on one test is a little harsh … if the teacher has been drilling her students for two weeks on this type of question … then the student should be able to answer it … why a teacher would teach children about fractions may be punitive anyway … need more context …
Hey, homework questions aren’t allowed in GQ!
How do we know OP isn’t that 3rd grade kid?
Occasional editor and writer of cookbooks here.
For amusement, the full force of SD GQ was mercilessly unleashed on this in What formula switches from pints to milliliters?
I wonder if the problem was machine-generated. There’s a template, and some values are thrown in, but there’s no correction to the English.
By weight or by volume?
Hey, it makes as much sense as your question.
(Answer: Neither. kg is a measure of mass, like oz but unlike lb. Foo!)
Huh? Mixed fractions are still taught here… Why would they be obsolete? I would expect omitting mixed fractions would be detrimental to teaching kids the concept in general.
ETA: should have read the whole (1/1?) thread!
Just because does not match the readout on a digital device does not in any way mean it’s obsolete or useless. The original question is not about measuring a quantity of units. It is an arithmetic problem and there is only one right answer. 1.33 is not the right answer no matter how many 3’s you add. The notation “1 1/3” represents an exact quantity.
I swear to God, if this turns into another “.999=1 ?” thread you’re gonna get a smack.
The problem says nothing about how much total water to use, except to say it must fill all three cups. Absent any details to the contrary, all three cups are presumed to have equal capacity of one cup, a standard measure. Therefore, 1/3 of the water goes in Cup A, 1/3 in Cup B, and 1/3 in Cup C.
In other words, 1/3 in each cup, which is exactly what the question asks for. The question is mute on the contents of the bottles, whether are they are the same size, or whether the are full at the start. It doesn’t matter if the bottles are 55-gallon drums. Only the cups are ever described as full. It only asks what fraction of the total volume of transferred water goes into each cup. 1/3.
I teach a lot of elementary math classes and this question really bothers me. I want to know the size of the water bottles that the mom is using to fill her cups before I can tell you what fractional part she’s using.
I see where you are going with that, but I think at the end of the day, it’s still a poorly written question. 
Mixed fractions are alive and well in the American store … 1 lbs 14 oz, 5lbs 2 oz, 4 ft 6-7/16 in, an extra peck on that bushel of corn …
So that’s where the rolled up newspaper is …
Hey, you brought it up, not me. But the fraction 1/3 cannot be represented exactly in decimal notation.
Cannot be determined with the information given.