Movement of the Decimal Point
🎬 Video Tutorial
How to Multiply Decimals by Powers of 10? (0:01)
When multiplying a number by 10, 100, or 1000, move the decimal point 1, 2, or 3 places to the right, respectively. For example:
- $12.34 \times 10 = 123.4$ (move 1 place)
- $12.34 \times 100 = 1234$ (move 2 places)
- $12.34 \times 1000 = 12340$ (move 3 places)
Moving the decimal point to the right makes the number larger.
How to Divide Decimals by Powers of 10? (0:36)
When dividing a number by 10, 100, or 1000, move the decimal point 1, 2, or 3 places to the left, respectively. For example:
- $12.34 \div 10 = 1.234$ (move 1 place)
- $12.34 \div 100 = 0.1234$ (move 2 places)
- $12.34 \div 1000 = 0.01234$ (move 3 places)
Moving the decimal point left makes the number smaller.
Examples of Moving the Decimal Point (1:02)
- Multiplication by 1000 means moving the decimal point 3 places to the right.
$$5.02 \times 1000 = 5020$$
- Division by 100 means moving the decimal point 2 places to the left.
$$4.21 \div 100 = 0.0421$$
How to Convert Between Units (Application of Decimal Point) (2:08)
To convert 2.8 meters to centimeters, multiply by 100 because 1 m = 100 cm.
- $2.8 \times 100 = 280$
- Therefore, 2.8 m is equal to 280 cm.
To convert 2.8 meters to kilometers, divide by 1000 because 1 m = $\frac{1}{1000}$ km.
- $2.8 \div 1000 = 0.0028$
- Therefore, 2.8 m is equal to 0.0028 km.
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