I am struggling with conservation of mass labs in 5th grade due to lack of accuracy on their part in measuring. I have tried a chemical reaction before and after, with a balloon over the flask, and also ice melting in a baggie before and after. In both cases, the students are not able to accurately measure on the triple beam balance, so they get different before and afters.
Has anyone else had this problem? Would digital balances be more accurate? My students have a lot of practice with the balances and the seem to do great with relative mass, i.e. figuring out which is heavier, but when it comes to accuracy, they are definitely off.