3/8+3/20

Let's evaluate: $\frac{3}{8}+\frac{3}{20}$

ⓘ To add fractions, put them over the same denominator, then add the numerators. We choose $40$, the least common multiple of $8$ and $20$. Multiplying the numerator and the denominator by the same number does not change the fraction: $\frac{3}{8}+\frac{3}{20}$ = $\frac{3\times 5}{8\times 5}+\frac{3\times 2}{20\times 2}$ = $\frac{3\times 5+3\times 2}{8\times 5}$

$\frac{3\times 5+3\times 2}{8\times 5}$

ⓘ Perform multiplications before additions and subtractions: $3\times 5$ = $15$, $3\times 2$ = $6$

ⅰ $8\times 5$ = $40$

$\frac{15+6}{40}$

ⓘ Calculate the numerator and denominator before dividing: $15+6$ = $21$

▶Result:   $\frac{21}{40}$

The numeric value of: $\frac{21}{40}$ equals:

▷ $0.525$