Buzz: Questions & Answers

Fill-in Inequalities

Bruce Sharp

I need my students to solve algebraic inequalities. Here is an example of a very basic question and it's code.

Type: F, Match
Var: big = 11..25
Var: small = 1..10
2) Solve. `b-$big$>=$small$`
a. b>=eval($big$+$small$)

The problem is that this question is currently impossible for Buzz to grade. I like the answer type math exact so it doesn't matter if they type spaces or not and they can preview that >= is how you type ≥. Unfortunately the server is confused as soon as it sees the > in an expression and stops looking after that so as long as the students type "b" and any <,>,=, or any combination of those it is counted correct. So if the answer is b>=2 they would get full credit for b=-100.

We attempted to get around this issue by separating the answer into 3 parts like this.

Type: F, Match
Options: Multiple
Score: 3, Partial
Var: big = 11..25
Var: small = 1..10
1) Solve. `b-$big$>=$small$`
Type the variable in the first blank, the inequality symbol in the second blank, and the number in the third blank.
______ ______ ______
[0.333333333333333]a. b
[0.333333333333333]b. >=
[0.333333333333333]c. eval($big$+$small$)

This will at least grade the number in the 3rd blank correctly. It still ignores the <,>,= in the middle blank though so in my earlier example where the correct answer should be b>=2 if a student types b=-100 they would still get 2 out of 3 points because the b is correct and the server ignores the symbol, but marks the -100 wrong.

The next best solution I could think of would be to change the answer type from math exact to normal. Unfortunately, that won't work either since an eval in an answer is only allowed for answer type number, math exact, or math equivalent.

I'm at an impass. The best solution I can think of (attention: FEATURE REQUEST!) is if I can set each answer blank to a different answer type. Then the first 2 blanks could be normal and the 3rd blank could be number or math exact so my eval would work.

Can your engineers think of any other way to get questions like this to work? Remember this is a very simplistic example. I also need it to work for more complicated inequalities and equations like -2/3x+7<5(x-8).


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