Adding and subtracting decimals are important skills for 8th graders. They help students get ready for more complicated math. Here’s how to do it in a simple way:

Step 1: Line Up the Decimals

• Make Sure They Line Up: Write the numbers one above the other. The decimal points should be in the same column. This helps you see what each digit means based on where it is.

For example:

   12.45
+  9.2

Step 2: Fill in Missing Zeros

• Add Zeros if Needed: If one number has fewer digits after the decimal point, add zeros to make them the same.

Using the previous example, it looks like this:

   12.45
+  9.20

Step 3: Do the Math

• Carry Over or Borrow: Start from the right side and move left. If you're adding and the total is more than ten, carry the extra over to the next column. If you’re subtracting and the top number is smaller, borrow from the next column.

Example of Addition:

Adding:

$$12.45 + 9.20 = 21.65$$

Example of Subtraction:

Subtracting:

$$12.45 - 9.20 = 3.25$$

Step 4: Write Down the Answer

• Don’t Forget the Decimal Point: Make sure the decimal point in your answer lines up with the decimal points in the numbers you added or subtracted.

Extra Tips:

• Practice Often: Studies show that students who practice decimals regularly can improve their skills by about 30% throughout the year.
• Use Real-Life Examples: Try using decimals when dealing with money or measuring things to make it easier to understand.

Conclusion:

Knowing how to add and subtract decimals is really important for 8th graders. By lining up the decimals, making any changes you need, and practicing a lot, students can grow their confidence and skills with decimal numbers. This will help them tackle future math challenges more easily.