Multiplying decimals is whole-number multiplying, then placing the point. That runs on quick multiplication facts, multiplying by 10 and 100, and reading decimal place value. Warm these up and decimal products stay in the right spot.
Answer these 3, then press Show my path. No grade — this just points you to the right level.
1. What is 7 × 8?
2. What is 6 × 10?
3. How many digits are right of the decimal point in 0.4?
To multiply decimals, first multiply as if there were no decimal points. Then count how many digits are after the point in both factors, and put that many after the point in your answer.
Your quick check picks one for you, but you can switch any time:
Level 0 Let's warm up facts and times-ten.
A. What is 3 × 4?
3 × 4 = 12.
B. What is 5 × 10?
Times 10 adds a zero: 5 × 10 = 50.
C. What is 7 × 6?
7 × 6 = 42.
Level 1 Now multiply a decimal by a whole number.
A. What is 0.3 × 2?
3 × 2 = 6, one digit after the point → 0.6.
B. What is 0.5 × 4?
5 × 4 = 20, one digit after the point → 2.0 = 2.
C. What is 12 × 100?
Times 100 adds two zeros: 12 × 100 = 1200.
Level 2 Warm-up straight into decimal × decimal.
A. What is 0.6 × 3?
6 × 3 = 18, one digit after the point → 1.8.
B. What is 0.2 × 0.3?
2 × 3 = 6, two digits after points total → 0.06.
1. What is 0.4 × 5?
4 × 5 = 20, one digit after the point → 2.0 = 2.
2. What is 0.7 × 2?
7 × 2 = 14, one digit after the point → 1.4.
You've practiced exactly what Lesson 1-6 uses. Time to dive in.
Start Lesson 1-6 →