Summing these two inequalities and then dividing by gives the stated inequality. First the XX checksum is calculated by summing the track starting times mod 255. The total score is calculated by summing all thirteen boxes, together with any bonuses. Market demand is calculated by summing all individual household demands. The probability of each final state is then obtained by summing over all such possibilities. Summing over all possible oscillators at all points in space gives an infinite quantity. Counting a finite set is equivalent to summing 1 over the set. Summing these component forces using vector addition yields the original force. Harold Pashler wrote a paper summing up the theoretical approaches to dual task interference. Archers score each end by summing the scores for their arrows. In his book, Jakes popularised a model for Rayleigh fading based on summing sinusoids. Summing these numbers, one finds again elements. Suppose that one is summing "n" values "x", for . This consists of summing over "all" time indices. It is generally known as the "Summing up party history" phase.