1 2/3 + -2 3/4 = -13/12 = -1 1/12 ≅ -1.0833333
Conversion a mixed number 1 2/3
to a improper fraction: 1 2/3 = 1 2/3 = 1 · 3 + 2/3 = 3 + 2/3 = 5/3
To find a new numerator:
a) Multiply the whole number 1 by the denominator 3. Whole number 1 equally 1 * 3/3 = 3/3
b) Add the answer from previous step 3 to the numerator 2. New numerator is 3 + 2 = 5
c) Write a previous answer (new numerator 5) over the denominator 3.
One and two thirds is five thirds
Conversion a mixed number -2 3/4
to a improper fraction: -2 3/4 = -2 3/4 = -2 · 4 + (-3)/4 = -8 + (-3)/4 = -11/4
To find a new numerator:
a) Multiply the whole number -2 by the denominator 4. Whole number -2 equally -2 * 4/4 = -8/4
b) Add the answer from previous step -8 to the numerator 3. New numerator is -8 + 3 = -5
c) Write a previous answer (new numerator -5) over the denominator 4.
Minus two and three quarters is minus five quarters
Add: 5/3 + (-11/4) = 5 · 4/3 · 4 + (-11) · 3/4 · 3 = 20/12 + (-33/12) = 20 + (-33)/12 = -13/12
For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of both denominators - LCM(3, 4) = 12. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 3 × 4 = 12. In the following intermediate step, it cannot further simplify the fraction result by canceling.
In other words - five thirds plus minus eleven quarters is minus thirteen twelfths.