1% or 10% of a number??

Question

My math teacher assigned percent of a #.
She went over it at school but that was about a week ago.(Spring Break)
I need help. It says use 1% or 10% to estimate the percent of each. Here is a example: 31% 0f 78. Can you give me the answer and how you got it so I can do the rest of the page.

So on the next one, 62% of 28, 62% would be 60% and 28 would be 2.8. then I would multiply 60 and 3 and get 180. Is that right?

or would the answers be 18?

Answer 1

Since 31 is close to a multiple of 10, find 10% of 78 which is just 7.8 or about 8, then multiply it by 3 (since 31 is about 30, 3 X 10) to get an estimate of 24.

Remember: to "estimate" you must round off BEFORE you calculate, not after.

Answer 2

The process of estimation is so that you can get an answer easily. You are not concerened with the exact answer only an approximation. When estimating ALL terms are rounded and then you perform the operation. So, 31% of 78 is 30% of 80 which is 24. 62% of 28 is 60% of 30 which is 18.

Answer 3

1. When taking % of a number change the % you're looking for to a decimal. 31% would be the same as .31..................... and that is .31 X's 78 = 24.18

When multiplying .31 X's 78 you get 2418 but remember you have to place your decimal correctly. The % has two whole numbers to the right of the decimal so place your decimal two places in the answer thus in between the 24 & 18 to make 24.18 for the answer.

You have two numbers to the right of the decimal.======================================================================\

62% of 60 would be .62 X's 60 = 37.2 = 37.20

Answer 4

Take 10% of 78=about 8. Now multiply 8 times 3 (30% is 3 times 10%) which gives you 24. Not an exact answer, but I believe she is asking you to show how you can use 10% or 1% to estimate the answer.

Answer 5

finding 10% of a # is easier than finding 30%....
here is your number written in decimal form - 78.000-all whole numbers actually can be written with a decimal point to the right and no fractional parts
* to find 10% of a number we can do it three ways
1. divide by 10
2. multiply by 0.1
3. move the decimal point over to the left by one space

Using any one of these - you will get 7.8
*if 7.8 is 10% of 78...then to get 30% all you have to do is multiply it by 3 (10 x 3 =30)

well I will estimate 7.8 to be about 8...
so 8 x 3 = 24
so 30% of 78 is about 24

* so now what is 1% of 78...
1.you can divide by 100 (1 per cent means one per hundred...which means divide by 100)
2. you can multiply by 0.01
3. you can move the decimal point two spaces to the left

-anyway, you get 0.78....which we will estimate is about equal to 1.

- add that to 24... and
so 31% of 78 is about 25.

but you could also check if your answer make sense...if you had 3 quarters ...that's 75 cents...close to 78...and 31% is about one third...which is 1 out of the 3 quarters...or 25 cents.

Answer 6

.31 x 78 = 24 If you have to round it off .30 x 78= 23 If I understood you correctly.

Answer 7

Where is your math book? the text book should explain how to do this.
How I would do it is 10% of 78 is 7.8 and 1 % of 78 is 0.78 so 31% would be 7.8(3)=23.4+0.78 so the answer would be 24.18 Hope this helps.

Answer 8

in ANY percentage problem just remember is over of equals percent over 100 then you cross multiply (is/of = %/100) in this case
x/78=31%/100
(31*78)/100 =
(2418)/100 =
24.18
so 24.18 is 31% of 78.

Answer 9

78
10% is 7.8
1% is .78
so 3*7.8 + .78
or
24.18
But, since you are estimating
31% is a little more than 30%
since 8 is a little more than 7.8, just use 3*8, or
24, which is close to 24.18

Answer 10

78*.31=24.18