MULTIPLE
CHOICE
6th grade / Number / Decimals / Scaling decimals / Multiply decimals by 10 100 1000
Due to the fact that our number system is base 10, multiplying decimal numbers by powers of 10 is relatively simple. The digits of the number move around, and there are maybe zeros to add or remove, but the other digits all stay the same. Remember that when we multiply numbers by any number greater than 1 they get bigger so check this once your done.
Let's get our terms straight.
factor x factor = product
23.45 x 100 = 2345
So for the sum 23.45 x 100 = 2345,
When we multiply by 10 the product is 10x bigger than the initial factor.
When we multiply by 1000 the product is 1000x bigger than the factor.
Note that in the example above, the decimal point of the product is not written down because the product is an integer.
Write the digital factor to be multiplied by a power of 10 down. Keep the digital point still and move all the digits of the digital factor to the left around it. If we are multipling by 10, all the digits move 1 column to the left. If we are multipling by 100, all the digits will move 2 columns to the left, and for multipling by 1000, it is 3 columns.
7.438 x 10 = 74.38
7.438 x 100 = 743.8
7.438 x 1000 = 7438
Another method is to keep the digits of the decimal number static and move the decimal point to the right. If the factor is 100 move it two places to the right, one for each of the zeros in 100. If you are not writing numbers down, this can be an easier method to visualise in your head.
0.0671 x 10 = 0.671
0.0671 x 100 = 6.71
0.0671 x 1000 = 67.1
Multiplying by a number greater than 1? Then product should be bigger than the original number!
Remember too that multiplying and dividing are inverse operations so you can always check a multiplication by dividing the product by whatever power of 10 you multiplied by and make sure you get the original value returned.
0.0671 x 100 = 6.71
6.71 รท 100 = 0.0671
With our quick math tests you will be revising "Multiply decimals by 10 100 1000" in 2 simple steps. The math in our tests consists of 16 questions that ask you to multiply by powers of 10 up to 1000 by moving the digits the correct number of columns to the left.
These math tests are designed to round off your learning experience here at Free Math Games by testing whether you can correctly recognize the math you have learned (in the multiple choice test) and that you can correctly enter the correct answers (in the writing test).
Make sure you have chosen the correct topic before starting! Although these tests are timed, try to relax and concentrate on getting the answers right at first - later you can try the tests again more quickly.
The two types of tests are:
Key features of our math tests include:
You should expect to score 8+ / 10 in each test before you select a new topic. It is a good idea to repeat the test for each topic you do after two weeks to "reinforce" the math for that topic
UXO * Duck shoot * The frog flies * Pong * Cat and mouse * The beetle and the bee
Rock fall * Four in a row * Sow grow * Choose or lose * Mix and match
This is a multiple choice activity similar to "What is it" in the Math lessons - you are shown a randomly selected question from the topic you are using. A selection of topic answers are displayed as a list. If you click/tap the speaker beside any answer you will hear the audio for that answer.
For each question, you must click on the answer that matches that question. If your answer is correct you will hear a bell and one star will be lit. The next question will be shown. If your answer is wrong, a box will open showing you what the correct answer was.
The test is timed, and the clock starts when you click the Start button. The clock stops when you click your final answer. At the end of your test a screen will tell you how many of the questions you got right and how long you took to complete the test.
The writing test checks whether you can type the correct answer using your keyboard. This test is also timed. You can do the test many times until you get a good score. To start the test, click on the "Writing test" sign in the navigation board, then click on the "Start the test" arrow.
A random problem from your selected topic is shown. Beneath the problem there is a white box into which you should type the answer. If you need a little help you can click on the "Help me" button for a tip. Only use the help if you really need to.
If you type the answer correctly your device will automatically light a star. If you have entered your answer and no star lights up, click on the tick or press Enter to check your answer. When you have tried all the questions, a screen will show you how many questions you answered correctly and how long it took.
* Try to score 8 out of 10 in both test before you choose a new topic *
* It is OK to do the tests many times if you need to *
Secondary math home | Math topics | Math lessons | Math games | Math tests
Preschool math | Elementary math | Secondary math
Site home page | Privacy policy | FAQ | Contact | Acknowledgements | Blog
Select your view: