3/8-7/9

Let's calculate: $\frac{3}{8}-\frac{7}{9}$

ⓘ Add fractions by using a common denominator and then adding their numerators. We choose $72$, the least common multiple of $8$ and $9$. Multiplying the numerator and the denominator by the same number does not change the fraction: $\frac{3}{8}-\frac{7}{9}$ = $\frac{3\times 9}{8\times 9}-\frac{7\times 8}{9\times 8}$ = $\frac{3\times 9-7\times 8}{8\times 9}$

$\frac{3\times 9-7\times 8}{8\times 9}$

ⓘ Perform multiplications before additions and subtractions: $3\times 9$ = $27$, $7\times 8$ = $56$

ⅰ $8\times 9$ = $72$

$\frac{27-56}{72}$

ⓘ The numerator and the denominator are computed before the division: $27-56$ = $-29$

▶Result:   $-\frac{29}{72}$

The numeric value of: $-\frac{29}{72}$ is:

▷ $\approx -0.4028$