The diagram shows two figures both measured in inches. Each inch represents 400 feet, however note that each inch is divided/graded into 8 parts. That means each section along every inch is equal to 400 divided by 8 and that equals 50. Hence, every line that is used in grading every inch equals 50 ft.
The spaceneedle measures;
SN = 1.4 inches
SN = 1 + 0.4 inches
SN = 400 + (400 x 0.5)
**This is because 0.4 on the scale drwaing shows 0.4 as half of an inch, so a sclae of 0.4 is actually 4/8 of an inch which 1/2 or 0.5**
SN = 400 + (200)
SN = 600 ft
The Eiffel tower measures;
ET = 2.5 inches
ET = 2 + 0.5
(As explained above, 0.5 is actually 5/8 of an inch, and therefore 0.625)
ET = 800 + (400 x 0.625)
ET = 800 + 250
ET = 1050
Therefore the difference in height of both landmarks is
Diff = ET - SN
Diff = 1050 - 600
Difference = 450
The results show that the Eiffel Tower is 450 ft taller than the Space Needle.