MULTIPLE
CHOICE
2nd grade / Addition / Mental calculations / 3-digit number plus multiple of 10
When we want to add a smaller number to a bigger number, there are sometimes shortcuts that make it easier. If the smaller number is 10 or a multiple of 10, adding that number to a bigger number just means increasing the tens column of the bigger number by the number of tens you are adding.
So, for instance, if you want to add:
248 + 30
all you need to do is add 3 to the tens column value which is 4, so you get 7 for the tens column. The rest of the big number stays the same, so the total addition looks like this:
248 + 30 = 278
In the same way, adding 419 and 70 gives:
419 + 70 = 489
It is the same idea if you want to add hundreds to 3 digit numbers but this time you would add to the hundreds column value by the number of hundreds you want to add. Adding units is often just going to affect the units column, so for instance, 271 + 5 = 276 because all we had to do was add 5 to the units column value to get an answer.
With our quick math tests you will be revising "3-digit number plus multiple of 10" in 2 simple steps. The math in our tests consists of 16 questions that ask you to use mental calculations to add the given number of tens to a three-digit number.
3 topics:
Three digit number plus units
Three digit number plus tens
Three digit number plus hundreds
Sometimes in math the most useful skill you can have is to be able to do complicated sums in your head, but don't worry, it's not magic, there's are techniques you can learn.
When we want to add a smaller number to a bigger number, there are sometimes shortcuts that make it easier. If the smaller number is 10 or a multiple of 10, adding that number to a bigger number just means increasing the tens column of the bigger number by the number of tens you are adding.
So, for instance, if you want to add:
30 + 248
all you need to do is add 3 to the tens column value which is 4, so you get 7 for the tens column. The rest of the big number stays the same, so the total addition looks like this:
30 + 248 = 278
It is the same idea if you want to add hundreds but this time you would add to the hundreds column value by the number of hundreds you want to add. Adding units is often just going to affect the units column, so for instance, 271 + 5 = 276 because all we had to do was add 5 to the units column value to get an answer.
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 *
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