Perseus number answers

this is an example of a question that requires a numeric input and two to do that so this case the the answer is negative 94 and so the student would be expected to type in negative 94 and this shows the different formats that that are that are permitted so to do that you select the answer type of text input number and when you do that you can give the correct answer in this case it's negative 94 it could also be you know a fraction let's let's just I'll give an example of one-third let's say the answer to this is one-third if I type 1 third in there and then move outside that box you see it converts it to this repeating decimal and even though it kind of converted that it is still internally represented as one-third and so if I say that I'm going to require simplification and not allowing exact answers the student couldn't type point 3 333 the student would still have to type one-third so I guess the first thing I want to point out is sort of don't let that alarm you this is not what the student would would have to type in fact the student would not be allowed to type that that's just how we represent it internally so the student would still have to type one-third which is which is as it should be I guess so there's a couple options here one is to require simplification and so in this case if the answer is is one-third if the require simplifications check the student wouldn't be allowed to answer 26 for example they would have to answer one third and that should almost always be the case anywhere on Khan Academy that we are looking for a rational answer that answer should have to be simplified unless it's a you know sort of a very basic fractions exercise where students haven't learned to simplify yet but once they've learned to simplify we expect them to always provide simplified answers the next option is to allow in exact answers this again should be used sparingly we try to allow students to use exact or we try to require students to give exact answers whenever possible but perhaps you know you know if you're doing something that you know really the only way to do it is with a calculator and you may round part way through that sort of thing then you can permit in exact answers to be given and you can specify what the maximum error that you want to allow and then it will accept you know the correct answer plus or minus that error the next thing that you can specify is the answer type and rather than going through all of these excuse me rather than going through all of these I would point you to the style guide which is always linked at the top of the question editor and in the style guide there's a section that goes over you know the the text input number format and tells you what these different answer types are so for example if you have number selected which is the default and probably what you want most of the time then it will accept integers decimals proper fractions improper fractions mixed numbers and you can always go here and select you know a particular thing let's say rationals you're not quite sure what that is if you hover over acceptable formats it should well it should tell you what what what it's going to accept and it looks like there might be a bug right now where it's not it's not actually rendering the examples it should say like an integer like six an exact decimal like 0.75 it should actually show that so looks like there's a bug but normally if you hover over this acceptable formats it will show you the different formats that that that will accept so for example place a percents acceptable format should allow a percent down there at the bottom if I if I just want mixed numbers it tells me I can only give integers proper fractions and mixed numbers so that will give you kind of a clue as to what these are normally you would want to just accept numbers if your answer can be expressed as a multiple of Pi then you want to select numbers with PI we we always prefer students to enter you know an answer like 2 pi as 2 pi because that is what the answer is we would prefer that they don't enter an answer like 6.28 because 2 pi is not equal to six point two eight and we want to make sure that students understand that so you know we always as much as possible want students to enter exact answers the next thing you can specifies the width and in in pretty much every case you want just a normal width and that's just the size of the text box there are other cases where you might have multiple answers and then you might want the text box to be a little bit narrower but in this case since we have a single answer we want to be the normal width and so there's no need to adjust that and I think that's pretty much it for the number answer type