What are the different ways that the simulation indicates when an equation is balanced?

Earth's axis of rotation is tilted at an angle of 23.5 degrees. what is one change you would see on earth if its axis was not tilted?

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?