Adding and subtracting decimals is just whole-number adding once the decimal points are lined up. That runs on reading place value (tenths, hundredths) and solid whole-number addition and subtraction. Warm these up and decimal math lines up neatly.
These are words you'll need to already know to follow this lesson — not the new words the lesson teaches. Review each one, its meaning, and the example so the new lesson makes sense from the start.
Level 1 What a digit is worth because of where it sits in a number.
Example: In 3.7, the 7 is in the tenths place, so it is worth 7 tenths.
Level 1 To put numbers together to find how many in all.
Example: 46 + 27 = 73.
Level 1 To take one number away from another to find what is left.
Example: 80 − 35 = 45.
Level 1 The first spot right after the dot, worth one part of ten.
Example: In 0.6, the 6 means 6 tenths.
These check the skills you'll need for this lesson — not the new lesson itself. Answer all 3, then press Show my path. No grade — it just suggests where to start.
1. In 3.7, what digit is in the tenths place?
2. What is 46 + 27?
3. What is 80 − 35?
Vocabulary previewed and basics checked. Time to start the lesson.
Start Lesson 1-5 →