Since August is the 8th month of the year, this means Kelli has called her grandmother 8 times so far since she calls her once a month
Since she calls her cousin every other month, Kelli has called her cousin 4 times so far because if she calls from January to August every other month, you would do 8÷2 because every other month = 2 months.
This means Kelli has called her grandmother 8 times
Therefore, 8+4=12.
Kelli so far has made 12 calls in total.