Open-answer questions rarely specify the answer format, and will thus accept only one of 0.5, 0.50, .5, 1/2, 4/8 ... etc while rejecting all the rest. Then the next question will not keep the same format.
Points for correct answers add to your score, but not linearly; points for incorrect answers subtract from your score, but not linearly.
Endlessly frustrating.
IXL is absolute garbage, as should be expected from any Pearson product. And the morons at Seattle Public Schools are dumping money into that dumpster fire like it's going out of style.
We don't try to be unfair; we're trying to make math fun. Please send a note to help@ixl.com if you run into questions that silently require a too-specific answer format, and we'll fix it.
Your product is terrible and anyone who likes math could have told you it was terrible from using it for 30 minutes.