1 7/9 + 6 9/27
First let's estimate the answer. 1 7/9 rounds up to 2. 6 9/27 rounds down to 6. 6+2 = 8. So we expect our answer to be around 8. Now let's do the problem
1 7/9 + 6 9/27 = (1 + 6) + (7/9 + 9/27)
= 7 + (7/9 + 9/27)
We need to put the fractions over a common denominator to add them. We could multiply 7/9 by 3/3 to change it to 21/27. But in this case, it's easier to reduce the 9/27 to 3/9, so let's do that:
= 7 + (7/9 + 3/9)
= 7 + 10/9
= 7 + 1 1/9
= 8 1/9 and our answer is around 8 as we estimated
