Lesson 4 of 10 · Grades 3 to 4
Practice: Multiplying by 10 and 100
Multiply by 10, by 100, and by tens such as 20 or 70. The pattern does most of the work. Ten questions follow, ending with a missing-number problem.
How to use this page
This page gives you ten more questions on the same idea as the lesson "Multiplying by 10 and 100". Work through them at your own speed. Write your answer down or say it out loud before you open the answer box, so you give yourself a real chance to think.
If a question feels hard, go back to the lesson and look at the worked example again. Getting a question wrong is useful; it shows you the part that needs one more look.
Practice questions
Answer all ten questions in your notebook or in your head. Then open each answer to check your work.
-
What is 4 × 10?
Show answer
40.
-
What is 40 × 10?
Show answer
400.
-
What is 8 × 100?
Show answer
800.
-
What is 12 × 100?
Show answer
1200.
-
What is 6 × 20?
Show answer
120. Think of 20 as 2 × 10, so 6 × 20 = 6 × 2 × 10 = 12 × 10 = 120.
-
What is 5 × 30?
Show answer
150. 5 × 3 = 15, then one zero gives 150.
-
A crate holds 100 oranges. How many oranges are in 17 crates?
Show answer
1700 oranges. 17 × 100 = 1700.
-
What is 9 × 70?
Show answer
630. 9 × 7 = 63, then one zero gives 630.
-
Tess buys 10 packs of cards. Each pack holds 24 cards. How many cards does she buy?
Show answer
240 cards. 24 × 10 = 240.
-
Fill the blank: 3 × ? = 3000. Explain how the zeros help.
Show answer
1000. 3 × 1000 = 3000. The product has three zeros, and 1000 supplies all three.