The expenditure approach to calculating GDP involves adding up the expenditures made on goods and services produced within a country during a specific time period. There are four main components of GDP under the expenditure approach:

1. Consumption (C): This includes all the expenditures made by households on goods and services, such as food, clothing, housing, and healthcare.

2. Investment (I): This includes all the expenditures made by businesses on capital goods (such as machinery, buildings, and equipment) and inventory, as well as expenditures made by households on new homes.

3. Government spending (G): This includes all the expenditures made by federal, state, and local governments on goods and services, such as defense, education, and healthcare.

4. Net exports (NX): This is the difference between a country's exports (goods and services sold to other countries) and its imports (goods and services purchased from other countries).

The formula for calculating GDP using the expenditure approach is:

GDP = C + I + G + NX

For example, if a country's consumption is $10 trillion, investment is $2 trillion, government spending is $3 trillion, and net exports are -$1 trillion (meaning imports are greater than exports), then the country's GDP would be:

GDP = $10 trillion + $2 trillion + $3 trillion - $1 trillion
GDP = $14 trillion

Therefore, the country's GDP would be $14 trillion.