On-Ramp · Grade 6 · 6.NOS.B.3

Adding & Subtracting Decimals: Line Up the Points

I can add and subtract decimals by lining up the decimal points.

📘 Word Bank + Sentence Frames

decimal pointline upplace valuetenths / hundredths

The one rule: stack the numbers so the decimal points are in a line, then add or subtract normally.
  • Fill empty spots with 0 to keep columns even.
  • Frame: "I lined up the decimal points, so the answer is ____."

👀 See It: A Worked Example

Add 1.2 + 0.45. Line up the points (write 1.2 as 1.20):

1.20
+0.45
1.65

The decimal points stay in a straight line. 1.2 + 0.45 = 1.65.

✏️ Your Turn

0 of 3 checks complete

1. 2.5 + 1.3 = ?

2. 4.00 − 1.25 = ?

3. Before adding 3.7 + 0.46, what should you do first?

💬 Explain Your Thinking

Explain the rule in your own words:

"When I add or subtract decimals, I first blank, because blank."