A scale written as a ratio in simplest form?

Answer 1

Convert the units of both sides to the same, then remove the units and simplify (if possible by dividing both sides by a common divisor greater than 1).

eg The Landranger series map scale of 2 cm equals 1 km:

1 m = 100 cm

1 km = 1,000 m

→ 1 km = 1,000 x 100 cm

= 100,000 cm

2 cm : 1 km

→ 2 cm : 1 x 100,000 cm

→ 2 cm : 100,000 cm

→ 2 : 100,000

→ 1 : 50,000