Floor Covering

[nycmathguy]

A contractor planned to cover a floor measuring 6.5 feet by 11.8 feet. Realizing that there would be a cabinet covering 2 square feet of the floor at one end of the room, he decided not to cover that portion of the floor. Since the floor covering is only available in multiples of 5 square feet, which amount should he order?


A. 75 sq. ft.
B. 80 sq. ft.
C. 85 sq. ft.
D. 70 sq. ft.

A bit tricky. Let me see.

How about 6.5 x 11.8 minus 2 square feet of the portion he did not cover.

6.5 x 11.8 = 76.7 minus 2 = 74.7.

If I round 74.7 to the nearest unit, I get 75 square feet. I know that 5 is a multiple of 75.

I say the answer is choice A.

 

[MathLover1]

correct

 

[nycmathguy]

correct

I must be dreaming. Word problems and I do not walk hand in hand.

 

[HallsofIvy]

"I know that 5 is a multiple of 75."

No, it's not. 75 is a multiple of 5.

 

[nycmathguy]

"I know that 5 is a multiple of 75."

No, it's not. 75 is a multiple of 5.

I got it backwards. In fact, what does it really mean that a number is a multiple of another? Does it mean that 75 is evenly divided by 5, in this case? However, we can also divide 5 by 75.

Let me see.

75 ÷ 5 = 15

5 ÷ 75 = 0.0666666667

Generally, what does it really mean for a number x to be a multiple of a number y?

 

[HallsofIvy]

I would only use the phrase in talking about integers. "x is a multiply of y" if and only if there exist an integer n such that x= ny.

 

[nycmathguy]

I would only use the phrase in talking about integers. "x is a multiply of y" if and only if there exist an integer n such that x= ny.

Talking to me like a textbook does not help.

 

[MathLover1]

I got it backwards. In fact, what does it really mean that a number is a multiple of another? Does it mean that 75 is evenly divided by 5, in this case? However, we can also divide 5 by 75.

Let me see.

75 ÷ 5 = 15

5 ÷ 75 = 0.0666666667

Generally, what does it really mean for a number x to be a multiple of a number y?

it was obviously a step error, but the order is important, it's not the same say 75 is a multiple of 5 and 5 is a multiple of 75 ... the difference is huge

 

[nycmathguy]

I would only use the phrase in talking about integers. "x is a multiply of y" if and only if there exist an integer n such that x= ny.

Don't talk like a textbook.

 

[HallsofIvy]

Do you mean "Don't be precise"?

 

[HallsofIvy]

Talking to me like a textbook does not help.

So you can only understand loose, sloppy talk! That's sad.

 

[nycmathguy]

So you can only understand loose, sloppy talk! That's sad.

When responding to me, you must talk in Math for Dummies language. Otherwise, I don't follow through most of the time. If you cannot break the material down to the level of students, why waste my time here? I should just continue with my textbook and enjoy every moment of confusion.

 

[HallsofIvy]

So "spoon feed"!

 

[nycmathguy]

So "spoon feed"!

Break down the material in a precise way. I don't expect anyone to spoon-feed me. I can stay afloat.