91Ó°ÊÓ

Integer operations are fundamental skills in mathematics that encompass addition, subtraction, multiplication, and division of whole numbers (integers). In this exercise, we are dealing with addition and subtraction of integers.
When adding or subtracting integers:
- If you add a positive number, move to the right on the number line.
- If you add a negative number, it's the same as subtracting its absolute value, so you move to the left on the number line.
- If you subtract a positive number, move to the left.
- If you subtract a negative number, it's the same as adding its absolute value, so you move to the right.
For example, in the exercise 612 + (-1.7), we see addition of a negative number, which is the same as subtraction. Thus, it converts to 612 - 1.7.

Absolute value refers to the distance of a number from zero on the number line, regardless of direction. It is always a non-negative number. For example, the absolute value of both -7 and 7 is 7 and denoted as \(|7| = 7\).
Understanding absolute value is crucial for operations involving negative numbers. In the exercise above, adding -1.7 to 612 uses the concept of absolute value because
\[ 612 + (-1.7) \text{ is the same as } 612 - |1.7|. \]
Here, we convert the negative addition into subtracting the absolute value of 1.7 from 612.

Subtraction of decimals is a common arithmetic operation. Just like subtracting whole numbers but with attention to the decimal places. To successfully subtract decimals:
- Align the decimal points of the numbers.
- If necessary, add zeros so that both numbers have the same number of decimal places.
- Subtract as with whole numbers, starting from the rightmost digit.
In this exercise, we subtract 1.7 from 612:
\[ 612.0 - 1.7 = 610.3 \]
Here, aligning the decimal points ensures accurate subtraction, leaving us with 610.3 as the final result.