Course summary field: Decimal place value, comparing decimals, and adding/subtracting them.
Decimals are just another way to write fractions, specifically fractions with 10, 100, or 1,000 on the bottom. Think of money: $0.75 means 75 cents, or 75/100 of a dollar.
Just like whole numbers, decimals have place value — but going the other direction from the decimal point:
Comparing decimals: line up the decimal points, then compare digit by digit from left to right . Just like comparing whole numbers.
Example 1 : Which is bigger, 3.08 or 3.8?
Line them up: 3.08 vs. 3.80 (adding a zero doesn’t change the value, it just helps us compare)
Compare the ones place: both are 3, tied so far
Compare the tenths place: 0 vs. 8 → 8 is bigger
Answer: 3.8 is bigger
💡 Watch out: More digits doesn’t mean a bigger number! 3.08 has 3 digits after the decimal counting the invisible zero, but it’s still smaller than 3.8.
Adding and subtracting decimals: line up the decimal points (this is the most important step. It’s like lining up ones with ones, tens with tens).
Example 2: 4.25 + 1.7
Its that easy! for more practice solve lesson 33&34 from our practice booklet.