Does anyone know the answer to these

53) The metric unit of mass is kilogram. It is the mass of a piece of platinum alloy that keep in a museum in Paris. One kg (kilogram) is equal to 1000 g (gram). One kg (mass) weighs 2.205 pounds on the surface of the Earth.

54) The unit used to measure weight in the metric system is the gram. Other metric units for weight include the kilogram, the metric ton and the milligram

55) not sure about this one

56)

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45