Multiplying by Any Fraction of 100, 1000, etc...

This trick extends the principles of multiplying by 25 and 75 to other numbers that can be expressed as simple fractions of 100, 1000, etc. This is especially common with fractions involving eighths, sixths, and thirds, often in approximation problems.

Examples:

• $125 = \frac{1}{8} \times 1000$
• $37.5 = \frac{3}{8} \times 100$
• $8333.3 \approx \frac{5}{6} \times 10000$

For approximation problems, you can estimate a number to the nearest convenient fraction. For example, a number like 670 might be approximated as $\frac{2}{3} \times 1000$.