The U.S. national debt was $2.9617×10^13 in 2021 and $3.98×10^11 in 1971. Find how much the debt increased in the 50-year period.

Answer 1

To find how much the debt increased, we need to subtract the debt in 1971 from the debt in 2021.

Debt increase = Debt in 2021 - Debt in 1971

Debt increase = 2.9617×10^13 - 3.98×10^11

To subtract these numbers, we need to make sure they have the same exponent.

2.9617×10^13 = 296.17×10^11 (moving the decimal point two places to the left)

Debt increase = 296.17×10^11 - 3.98×10^11

Now that the exponents are the same, we can simply subtract the numbers in front:

Debt increase = (296.17 - 3.98) × 10^11

Debt increase = 292.19 × 10^11

The debt increased by $292.19 × 10^11, or in scientific notation, $2.9219×10^13.