Question

I will reward with fan and medal for whoever helps. Which number would you add to three and nine-tenths to give an approximate sum of 6?

Two and one-thirds

Three and two-elevenths

One and one-twelfths

Two and seven-eighths

Answer 1

\[6 = 3\frac{ 9 }{ 10 } + x\]

Answer 2

ok

Answer 3

If you set your fraction back into and improper and subtract it from both sides,
\[3\frac{ 9 }{ 10 } = \frac{ 39 }{ 10 }\]

\[6 = \frac{ 39 }{ 10 } + x\]

\[6 - \frac{ 39 }{ 10 } = x\]

Answer 4

Now finding the least common denominator to be 10 we set 6 as an improper fraction.
\[6 = \frac{ 60 }{ 10}\]
So that we now have:
\[\frac{ 60 }{ 10 } - \frac{ 39 }{ 10 } = x\]
If we subtract we find the x.
Where x is the missing number we would add to get 6

Answer 5

I still dont understand that last part

Answer 6

Which last part?
I changed the 6 into an improper fraction so that we would have a common denominator so that they will be able to subtract from one another.

Answer 7

So if you subtract:
\[\frac{ 60 }{ 10 } - \frac{ 39 }{ 10 }\]
What do we have?

Answer 8

21/10

Answer 9

Correct and we can simplify that further because we know that 10 goes into 21 2 times.

Answer 10

okay so the 2 will be the whole number in the mixed number?

Answer 11

Yes, and then we will only have a 1 left so that we are left with:
\[2\frac{ 1 }{ 10 }\]

Answer 12

okay thanks so much

Answer 13

No problem