We had a day like that yesterday. Snow falling still, mom and boy with no desire to do school so we opted out.. we did a Project instead.. we worked on building a bigger feeder for the lad's mice... we'll need to rework it a bit more yet. :) But it gave us a time to problem solve, to work with new materials, and to communicate with each other differently over our schooling/work. It was a fun way for us to do math that seems practical rather than "AH MORE WRITING!!!
If you need a different option for doing math, Educents just might have the answer for you.