Understanding Decimal Addition and Subtraction
Decimals are numbers with a point that show parts of a whole.
When adding or subtracting decimals, the most important rule is to line up the decimal points! This keeps all the place values in the correct columns - ones with ones, tenths with tenths, and so on.
Steps to Success
1️⃣ Line up the decimal points (add zeros if needed)
2️⃣ Add or subtract just like with whole numbers
3️⃣ Bring down the decimal point in your answer
Let's Practice Together!
Example 1: Adding Decimals
Sarah bought 2.35 kg of apples and 1.6 kg of oranges. How much fruit did she buy in total?
First, line up the decimals by adding a zero to 1.6:
\[ \begin{array}{r} \phantom{0}2.35 \\ +\phantom{0}1.60 \\ \hline \phantom{0}3.95 \\ \end{array} \]
Sarah bought 3.95 kg of fruit in total!
Example 2: Subtracting Decimals
James had \$5.75. He spent \$2.90 on a toy. How much money does he have left?
Line up the decimals and subtract:
\[ \begin{array}{r} \phantom{0}5.75 \\ -\phantom{0}2.90 \\ \hline \phantom{0}2.85 \\ \end{array} \]
James has \$2.85 left!
Parent Tips 🌟
- Money makes sense: Use real coins and bills to practice adding and subtracting decimals - kids understand money concepts naturally!
- Line it up game: Create a game where your child has to spot incorrectly lined up decimal problems - make it fun with rewards!
- Daily practice: Incorporate decimal problems into everyday activities like cooking ("We need 0.25 cups more flour") or shopping ("This costs \$3.99, how much change from \$5?")