Scale drawings: word problems

Learn with an example

  • Write a ratio that represents the scale of the map in centimetres to kilometres: 1/1,
  • Write a ratio that relates the centimetres between the state park and the closest state beach on the map to the kilometres between the state park and the closest state beach in real life: 9/d,
  • Use those ratios to set up a proportion and solve.
  • 1/1 = 9/d
  • 1/1 ( d ) = 9/d ( d ) ——-> Multiply both sides by d
  • d = 9 ——-> Simplify
  • In real life, the distance between the national park and the closest state beach is 9 kilometres.
  • Write a ratio that represents the scale of the map in centimetres to kilometres: 1/10.
  • Write a ratio that relates the centimetres between the two petrol stations on the map to the kilometres between the two petrol stations in real life: 7/d.
  • Use those ratios to set up a proportion and solve.
  • 1/10 = 7/d
  • 1/10 ( 10d ) = 7/d ( 10d ) ——-> Multiply both sides by 10d
  • d = 10 · 7 ——–> Simplify
  • d = 70 ———> Simplify
  • The actual distance between the two petrol stations is 70 kilometres.
  • Write a ratio that relates the centimetres between the two stations on the map to the kilometres between the two stations in real life: 6/2.
  • To find the scale of the map, rewrite this ratio in simplest form using whole numbers.
  • 6/2 = 3/1 —–> Divide the numerator and denominator by the GCF, which is 2
  • The map’s scale is 3 centimetres = 1 kilometre.

Let’s practice! 🖊️