Reading 25: Pg. 117, Approx Number of futures contract formula

CFA Level III
#1

I am confused about origination of below formula on Pg 117 of Volume 4, Reading 25

Approximate number of contracts = (Dt - Di) Pi / (dollar duration per futures contract)

I was thinking the numerator need to divided by 100 in order to get dollar duration such that (dollar duration) / (dollar duration per futures contract) = no. of contracts

The numerator right now in the formula is D*P, shouldn’t it be (Dt - Di)Pi /100?

Please help me understand on what am I missing? Thanks

#2

dt - di = dollar duration on the top and you are dividing by dollar duration of the futures contract. since both would have a /100 - which would cancel out, you end up with the above formula.