Understanding Significant Digits
* Non-zero digits are always significant. (e.g., 1, 2, 3, etc.)
* Zeros between non-zero digits are significant. (e.g., 102, 3005)
* Leading zeros are NOT significant. (e.g., 0.025)
* Trailing zeros are significant ONLY if there's a decimal point. (e.g., 200.0 has 4 significant digits, but 200 has only 1)
Applying the Rules
* 1111 km has four significant digits.
* 222 has three significant digits.
The Problem
The problem is that we're adding a measurement in kilometers (km) to a number without any units. To add them together, we need to assume that the '222' is actually '222 km'.
Adding and Rounding
1. Add the values: 1111 km + 222 km = 1333 km
2. Determine the least number of significant digits: Both 1111 km and 222 km have three significant digits.
3. Round the result: Since the result (1333 km) has four significant digits, we need to round it to three significant digits. The answer becomes 1330 km.
Important Note: It's always best to include units in your calculations and final answers to avoid confusion and ensure accuracy.
