Why does multiplying numbers by 10 move the decimal point to the right, but multiplying by 0.10 moves the decimal point to the left?

Awall map has a scale of 128 miles = 6 inches. the distance between springfield and lakeview is 2 feet on the map. what is the actual distance between springfield and lakeview? 384 miles 512 miles 1.13 miles 42.7 miles

Quadrilateral abcd in the figure below represents a scaled-down model of a walkway around a historic site. quadrilateral efgh represents the actual walkway. abcd is similar to efgh. what is the total length, in feet of the actual walkway?

Liz had 140 pens and inna had 100 pens. after inna gave liz some pens, liz had 3 times as many pens as inna. how many pens did inna give liz?