To multiply decimals by 10, 100, and 1000, use place value labels. Write the digits of the decimal using place value labels. Start with the first non-zero digit. To multiply by 10 move each digit one ...

When you multiply decimals by integers (whole numbers), you can use everything you already know about multiplying multi-digit numbers. You can use written or mental methods to multiply decimals by ...

Numberphile revived an ancient multiplication trick—halves and doubles—also called Egyptian or Russian math, where you repeatedly halve one number and double the other. After crossing out rows with ...