5. \( \quad 489.21 \div 0.25 \)

To perform the division \( 489.21 \div 0.25 \), you can simplify the process by converting the divisor into a whole number. Multiply both the dividend and the divisor by 100 to eliminate the decimal: \( 489.21 \div 0.25 = 48921 \div 25 \). Now, you can perform the division, which results in \( 1968.84 \). And there you have it! --- Did you know that dividing by a fraction is the same as multiplying by its reciprocal? So instead of dividing by 0.25, you could also multiply by 4 (since 0.25 is equivalent to \( \frac{1}{4} \)). This nifty trick can save you time and keep your calculations neat! Another fun tidbit: decimals weren’t widely used until the 16th century, thanks largely to the work of mathematicians like Simon Stevin. Before this, folks relied on fractions for all sorts of calculations—imagine the added complexity! This transition to decimals has made everything from basic math to complex engineering calculations much simpler!