Question

Karissa determines the area of her desk by multiplying 45.72 centimeters and 60.95 centimeters. She states that the area is 2786.634 square centimeters. Which best describes the reasonableness of Karissa’s solution?

a.The solution is unreasonable because 50 times 60 is 3,000, not 2,786.

b.The solution is reasonable because is 50 times 60 3,000, which is close to the computed area.

c.The solution is unreasonable because there are four decimal places in the factors and only three decimal places in the product.

d.The solution is reasonable because there are four numbers to the left of the decimal in the factors and four numbers to the left of the decimal in the product.

Answer 1

I believe it is .The solution is reasonable because is 3,000, which is close to the computed area.

Answer 2

Answer: .The solution is reasonable because is 50 times 60 =3,000 , which is close to the computed area.

Explanation:

Given: Karissa determines the area of her desk by multiplying 45.72 centimeters and 60.95 centimeters.

If we round the given values to the nearest tens, we get

`45.72\rightarrow50\\\\60.95\rightarrow60`

Now, the approximate area of the desk =
`50*60=3000\text{ square centimeters }`

Since, the area calculated by Karissa = 2786.634 is close to 3000 if we round it to the nearest thousand.

Therefore, the solution is reasonable .