b) \( 1-0.3431 \) c) \( 0.001+0.009 \)

Did you know that the first decimal number system dates back to ancient civilizations like the Babylonians, who used a base-60 system? However, the decimal system as we know it now was popularized by Indian mathematicians and then brought to Europe through Arabic translations. It made calculations a whole lot simpler and is something we still rely on today! In real life, understanding how to add and subtract decimals is crucial! For example, when shopping, if a shirt costs $34.31 and you want to know how much you’d spend if you also buy socks for $1.00, you’d need to add those decimals together to get a total of $35.31. So, mastering these skills can make you a savvy shopper!