One way to do the problem is to just treat it as a multiplication problem and line it up that way and then move the decimal do the left according to how many decimal places there are after the decimal in the question....
How do you multiply this together by lining up the decimals? Thanks!
How do you do this problem? 10.75 times 3.2?
2008-03-29 5:12 pm
回答 (25)
2008-03-29 5:15 pm
✔ 最佳答案
You can't. The only time you line up the decimals is when you're adding an subtracting. The way you stated above is the correct way to do this without a calculator. 
2008-03-29 5:22 pm
Yahoo messes up the spaces, so I'm going to put in underlines instead:
_ _ _ _ 1 0 . 7 5
_ _ _ x _ 3 . 2
work:
_ _ _ _ 2 1 5 0
_ _ _ 3 2 2 5
add:
_ _ _ 3 4 4 0 0 <== almost the answer
To get the decimal place, round off the problem to 10 x 3 = 30. So the final answer is 34.4.
_ _ _ _ 1 0 . 7 5
_ _ _ x _ 3 . 2
work:
_ _ _ _ 2 1 5 0
_ _ _ 3 2 2 5
add:
_ _ _ 3 4 4 0 0 <== almost the answer
To get the decimal place, round off the problem to 10 x 3 = 30. So the final answer is 34.4.
2008-03-29 5:19 pm
To multiply the problem by lining up the decimals, you have to add a zero behind 3.2 since it does not change the value of the number:
10.75
X 3.20
(It may not line here, but you get the idea)
The answer is now 34.40, which is simplified as 34.4
10.75
X 3.20
(It may not line here, but you get the idea)
The answer is now 34.40, which is simplified as 34.4
2008-03-29 5:17 pm
= 10.75 * 3.2
= 34.4
Answer: 34.4
Check (going back to 10.75):
= 34.4/3.2
= (34 2/5)/(3 1/5)
= (172/5)/(16/5)
= 172/5 * 5/16
= 43/4 or 10 3/4 or 10.75
= 34.4
Answer: 34.4
Check (going back to 10.75):
= 34.4/3.2
= (34 2/5)/(3 1/5)
= (172/5)/(16/5)
= 172/5 * 5/16
= 43/4 or 10 3/4 or 10.75
2008-04-01 6:20 am
10.75 times 100 = 1075
3.2 times 10 = 32
1075 times 32 = 34400
34400 / 1000 = 34.4 ( the 1000 come from 10 times 100 )
therefor
10.75 times 3.2 = 34.4
3.2 times 10 = 32
1075 times 32 = 34400
34400 / 1000 = 34.4 ( the 1000 come from 10 times 100 )
therefor
10.75 times 3.2 = 34.4
2008-03-29 5:28 pm
34.4 is the awnser and here is a trick, all you have to do is remove the decimals from the problem, like this 10.75 to 1075 and count how many times the decimal moves to the left so in this case twice, then do that with 3.2 to 32 and the was once. Now just multiply 32 and 1075. With the awnser you with that (I hope you know the decimal is at the end of the answer like this 34400.) Now just move it to the right 3 times and you have your answer, just dont forget the decimal at the end. Hope this helped you, this trick is very effective!
2008-03-29 5:25 pm
multiply 32 by 1075 and then move the decimal three places to the right
2008-03-29 5:24 pm
put a zero after the 2 because then you will have
10.75
x 3.20
and that should match ur decimals up... and adding the zero will not change your answer which is 34.4
10.75
x 3.20
and that should match ur decimals up... and adding the zero will not change your answer which is 34.4
2008-03-29 5:21 pm
easy way...take out the decimals first...1075x32=34400...move decimal three places...34.4
2008-03-29 5:15 pm
just put zero after two.or to simply remove the decimal point multiply the two by 100
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