What is the formula of the compound between calcium and sulfur that has the percent composition 55.6% calcium and 44.4% sulfur

We are given with two elements and their respective percent composition. Having a 100 grams basis, we convert each mass to moles. Calcium is equivalent to 1.39 moles and sulfur equal to 1.3849 moles. We divide each from the smaller number between the two. Hence, Ca is 1 and S is also 1. The compound formula is CaS or calcium sulfide.