how to calculate the number $6.8?

Question 21: Complete the following statements about the budget balance. . If the economy is operating well below potential/full-employment output, then cyclically adjusted budget balance deficit is likely to SMALLER (smaller /greater/the same) than/as the actual budget balance. . Suppose that country's debt is $7 billion at the beginning of the fiscal year. During the fiscal year, the government spending is $1.8 billion, tax revenues equal $2.7 billion, and transfer payments reach $0.7 billion. At the end of the fiscal year, the debt is $6.8 billion