Question

Joseph wants to estimate 1 3/7 times 5 4/5 . To estimate, he simplifies the expression 1 1/2 times 6 . Is Joseph's estimate a close estimate, an underestimate, or an overestimate?

A. underestimate

B. overestimate

C. close estimate

Answer 1

@mathstudent55

Answer 2

Notice which numbers he is using for the estimate.
He is using 1 1/2 instead of 1 3/7.
Is 1 1/2 greater than or less than 1 1/2?

Answer 3

Then look at the second number he is using.
He is using 6 instead of 5 4/5.
Is 6 greater than or less than 5 4/5?

Answer 4

well the first one is equal to n the second one is more than

Answer 5

Look at the fraction 3/7.
Is 3 less than, equal to, or greater than 7?

Answer 6

no i mean u said " is 1 1/2 greater then or less than 1 1/2

Answer 7

ok what ever lol bother r greater than

Answer 8

both r*

Answer 9

Sorry. In the first number, I meant is 1 1/2 greater than or less than 1 3/7?

Answer 10

Yes, you are correct. 1 1/2 is greater than 1 3/7 since 1/2 is greater than 3/7.

Answer 11

Now for the second number, is 6 greater than 5 4/5?

Answer 12

its greater than

Answer 13

Yes, both number he is using are greater than the real numbers.
1 1/2 is greater than 1 3/7.
6 is greater than 5 4/5.
Since both numbers he is using are greater than the real numbers, his estimate has to give him an answer that is greater than the real answer. That means he must be over estimating.

Answer 14

@Kayla369 , @haleyelizabeth2017
Do you understand it now?

Answer 15

Yes, I do :) I just didn't know the difference between close and overestimate :) I don't think I ever learned this :/

Answer 16

In this case we have a definite over estimate because to make the estimation easier, both original numbers were replaced with greater numbers. Since both numbers used for the multiplication are larger than the original numbers, the estimate has to be greater than the real result. This is an over estimate.

Answer 17

A case of an underestimate is where both numbers are replaced by lower numbers.
For example, if you are asked to multiply 3 1/8 * 4 1/7.
You can round 3 1/8 to 3, and you can round 4 1/7 to 4.
Then 3 * 4 = 12.
12 is an estimate, but it is definitely an underestimate because both numbers were rounded down to simplify the multiplication.

Answer 18

Okay, that makes a lot more sense :)

Answer 19

A case of a close estimate is where you round one number up and you round the other number down. For example, estimate 8 1/8 * 7 7/8
I'll round 8 1/8 down to 8
I'll round 7 7/8 up to 8
8 * 8 = 64, so 64 is a close estimate.