Final answer:
To calculate the total national debt at the end of 2014, you sum the starting debt of 1.8 x 10^13 dollars with the additional debt of 3.3 x 10^11 dollars, yielding a total debt of 2.13 x 10^13 dollars.
Step-by-step explanation:
To find the total national debt at the end of 2014, we need to add the debt at the beginning of the year to the debt incurred during 2014. The national debt at the beginning of 2014 was approximately 1.8 x 1013 dollars, and the debt grew by 3.3 x 1011 dollars during the year. To calculate the total debt at the end of 2014, sum these two amounts:
Total debt at end of 2014 = 1.8 x 1013 + 3.3 x 1011
To perform the addition, align the exponents by converting 3.3 x 1011 into 0.33 x 1013. So, the calculation now is:
Total debt at end of 2014 = 1.8 x 1013 + 0.33 x 1013
Now add the two amounts:
Total debt at end of 2014 = (1.8 + 0.33) x 1013
Total debt at end of 2014 = 2.13 x 1013 dollars.