An easy way of solving fraction questions with large numbers

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
Hello! I have a question about fractions. I'll be glad if someone can help me with that.

12205
*** That is 2008

In such questions, am I supposed to calculate it or is there a faster way?

Thanks a lot!
 

tkhunny

Moderator
Staff member
Joined
Apr 12, 2005
Messages
10,214
Hello! I have a question about fractions. I'll be glad if someone can help me with that.

View attachment 12205
*** That is 2008

In such questions, am I supposed to calculate it or is there a faster way?

Thanks a lot!
Addition is associative and commutative.

(2009 + 5/3) - (2008 + 2/3)

2009 + 5/3 - 2008 - 2/3

2009 - 2008 + 5/3 - 2/3

(2009 - 2008) + (5/3 - 2/3)
 

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
Addition is associative and commutative.

(2009 + 5/3) - (2008 + 2/3)

2009 + 5/3 - 2008 - 2/3

2009 - 2008 + 5/3 - 2/3

(2009 - 2008) + (5/3 - 2/3)
Thanks!
 

Subhotosh Khan

Super Moderator
Staff member
Joined
Jun 18, 2007
Messages
19,024
Hello! I have a question about fractions. I'll be glad if someone can help me with that.

View attachment 12205
*** That is 2008

In such questions, am I supposed to calculate it or is there a faster way?

Thanks a lot!
I would observe

\(\displaystyle \dfrac{5}{3} \ = \ 1\dfrac{2}{3}\)

and then

\(\displaystyle 2009\dfrac{5}{3} \ = \ 2010\dfrac{2}{3}\)

thus the answer is = 2
 

topsquark

Full Member
Joined
Aug 27, 2012
Messages
496
Am I the only one to see \(\displaystyle 200 \delta\) in the OP?

-Dan
 

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
I would observe

\(\displaystyle \dfrac{5}{3} \ = \ 1\dfrac{2}{3}\)

and then

\(\displaystyle 2009\dfrac{5}{3} \ = \ 2010\dfrac{2}{3}\)

thus the answer is = 2
Thank you! I didn't see that.

Am I the only one to see \(\displaystyle 200 \delta\) in the OP?

-Dan
Yes my bad, I couldn't write 8 properly on Math input panel. It is 2008.
 
Last edited:

LCKurtz

Junior Member
Joined
May 3, 2019
Messages
116
You accidentally typed "200\delta" instead of "2008" in the tex box? Trouble finding the 8 key?
 

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
You accidentally typed "200\delta" instead of "2008" in the tex box? Trouble finding the 8 key?
In Math input panel you write it with mouse and as far as I could observe if you write 8 starting from right to left it types a delta rather than eight. You should write it starting from left to right. I didn't know this difference at that time and no matter how many times I wrote 8 it typed a delta there. So I kept it this way and noted that it's an eight on the bottom in my message.

Also, you can right click the number/symbol and correct it. It gives you options to choose which number/symbol you want to change it to. But as I said I didn't know that at that time. I am a beginner with this software, just as I am in Maths.
 
Last edited:

LCKurtz

Junior Member
Joined
May 3, 2019
Messages
116
In Math input panel you write it with mouse ...
Aahhh, I see the problem. Trying to type with a mouse. Square peg, round hole...:confused:
 

Dr.Peterson

Elite Member
Joined
Nov 12, 2017
Messages
5,010
I'd never heard of Math Input Panel; I just tried it, and it made ridiculous errors. Maybe you should try something else (though once you learn how to correct errors, it appears to be at least workable if you're patient). Latex is not too hard for simple expressions.
 

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
I'd never heard of Math Input Panel; I just tried it, and it made ridiculous errors. Maybe you should try something else (though once you learn how to correct errors, it appears to be at least workable if you're patient). Latex is not too hard for simple expressions.
Thank you for your suggestion, I will learn more about it.
 

mmm4444bot

Super Moderator
Staff member
Joined
Oct 6, 2005
Messages
10,378
Hello d.mehdoi. As another alternative, you can simply type mixed numbers -- like '2009 and 5/3rds' -- by replacing the word 'and' with a plus sign. Also, grouping symbols help distinguish individual mixed numbers, and they are often required to show the proper order of operations (eg: both numbers 2008 and 2/3 are being subtracted, below):

[2009 + 5/3] - [2008 + 2/3] \(\;\) is correct

2009 + 5/3 - 2008 + 2/3 \(\;\) is not

For more help learning how to type math expressions using a keyboard, check out the link from the forum guidelines titled, "Formatting Math as Text". Cheers

😎
 

d.mehdoi

New member
Joined
May 14, 2019
Messages
14
Hello d.mehdoi. As another alternative, you can simply type mixed numbers -- like '2009 and 5/3rds' -- by replacing the word 'and' with a plus sign. Also, grouping symbols help distinguish individual mixed numbers, and they are often required to show the proper order of operations (eg: both numbers 2008 and 2/3 are being subtracted, below):

[2009 + 5/3] - [2008 + 2/3] \(\;\) is correct

2009 + 5/3 - 2008 + 2/3 \(\;\) is not

For more help learning how to type math expressions using a keyboard, check out the link from the forum guidelines titled, "Formatting Math as Text". Cheers

😎
Hello mmm4444bot, thank you! That website will be very helpful.
 
Last edited:
Top