When calculating global population growth, the death rate is

When calculating global population growth, the death rate is subtracted from the birth rate

Using just these variables, Population growth = Population*(Birth rate - Death rate). However, a couple of real-life refinements: 1. Although the number of births and deaths …depends on the population, it is related to the age-structure of the population. A very old population, for example, will not have many births but many deaths whereas a young population will have more births and fewer deaths. So, the population should be stratified according its age structure. 2. Net migration also needs to be taken into account.      

Sorry i don’t know what to do