16/19-9/20

Let's evaluate: $\frac{16}{19}-\frac{9}{20}$

ⓘ To add fractions, put them over the same denominator, then add the numerators. We choose $380$, the least common multiple of $19$ and $20$. Multiplying the numerator and the denominator by the same number does not change the fraction: $\frac{16}{19}-\frac{9}{20}$ = $\frac{16\times 20}{19\times 20}-\frac{9\times 19}{20\times 19}$ = $\frac{16\times 20-9\times 19}{19\times 20}$

$\frac{16\times 20-9\times 19}{19\times 20}$

ⓘ Perform multiplications before additions and subtractions: $16\times 20$ = $(10+6)\times 20$ = $10\times 20+6\times 20$ = $200+120$ = $320$, $9\times 19$ = $9\times (10+9)$ = $9\times 10+9\times 9$ = $90+81$ = $171$

ⅰ $19\times 20$ = $(10+9)\times 20$ = $10\times 20+9\times 20$ = $200+180$ = $380$

$\frac{320-171}{380}$

ⓘ Calculate the numerator and denominator before dividing: $320-171$ = $149$

▶Result:   $\frac{149}{380}$

The numeric value of: $\frac{149}{380}$ equals:

▷ $\approx 0.3921$