Decimal point movement is a technique used frequently in the metric system for converting units. When you divide by 10, 100, or 1000, you adjust the decimal point to the left by one, two, or three places, respectively. This technique is particularly useful when converting metric units because the system is based on powers of ten.
In the original problem, you need to move the decimal to convert from grams to kilograms. Here's how it works:
- Start with the number you have, which is 400 grams.
- Since 1 kilogram = 1000 grams, move the decimal point three places to the left: 400.0 -> 40.0 -> 4.0 -> 0.4.
- This transformation shows that 400 grams is equivalent to 0.4 kilograms.
Remember, the direction in which you move the decimal point depends on whether you are converting to a larger or smaller unit. Moving left makes the number smaller, which aligns with converting to larger units like kilograms.