David in rang 6 was learning all about bones and used a bone mould to fashion curds and whey into a bone shape. He was interested to learn that bones need calcium to become strong and healthy. He separated the milk into curds and whey using vinegar. Acids can really change substances and this was certainly the case in this experiment.
Adding the vinegar caused the milk to curdle. The resulting curds were scooped out and fashioned into a bone shape using a mould.