how much space is left on the poster.

Question

Sienna is making a poster for science class.  The length of the poster is 2 1/2 feet and its width is 1 1/4 feet> Sienna says that she will glue pictures  on 1 3/4 of the area of the poster and leave the remaining area for a title. her mother suggust that Sienna glue pictures on 4/5 of the poster and leave the reamining area for a title.

 

Part A Explain why is is possible for Sienna  to glue pictures on 4/5 of the area of the poster, but it is not possible for her to glue pictures on 1 3/4 of the area of the poster.

 

Part B What is the area, in square feet, of the poster? Write the answer as a mixed number.

Answer 1

Part A: If I'm understanding correctly, it's not possible to use 1¾ of the area of a poster because that's like saying you were going to use 175% of the area of the poster when it's only possible to use 100%. However, it is possible to use 4/5 of the area of the poster because that is 80%, which is less than 100%.

Part B: You can find the area by multiplying the base (a.k.a. the width) times the height (a.k.a. the length). To finish with a mixed number, it may be easier to convert to fractions before multiplying (i.e. 2½ feet = 5/2 feet, 1¼ ft = 5/4 feet).