Question

456.9 - 58.3=
78 x 125=
67.8 x 2.5=

Explanation:

Step1: Subtract decimals directly

$456.9 - 58.3 = 398.6$

Step2: Split 78 for easy multiplication

$78 \times 125 = (80-2) \times 125 = 80\times125 - 2\times125 = 10000 - 250 = 9750$

Step3: Convert 2.5 to fraction for calculation

$67.8 \times 2.5 = 67.8 \times \frac{5}{2} = 33.9 \times 5 = 169.5$

Answer:

$456.9 - 58.3 = 398.6$
$78 \times 125 = 9750$
$67.8 \times 2.5 = 169.5$