Abigail is going for a hike. After 6 km, she has gained 800 m in elevation. She stops for a break, then turns around and returns the way she came. What was her total change in elevation when she finished the hike?

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents