Examples of addition and subtraction within 20. Mathematical corner in the country

reservoirs 20.07.2020

reservoirs

Addition and subtraction tables are used to teach children to count or to test their skills in addition and subtraction. These two tasks use different tables. Both versions of the tables can be downloaded and printed on this page

Addition table up to 20 print and download

The addition table is used to teach children. The vertical leftmost column and the horizontal top row are summands. In order to add two numbers, you need to find them in a vertical column and in a horizontal row. The intersection forms the sum of these two terms. For example, as shown in the figure below, 6 + 5 = 11.

You can print the addition table up to 20 in Word or PDF format. If you need an addition table up to 10, it can be easily done by deleting unnecessary cells in the Word format. If you need an addition table more than up to 20, then you can download the addition table in Excel format and add the necessary columns and rows by copying.

Subtraction table up to 20 print and download

The subtraction table uses the same addition table that can be printed above. Suppose we need to solve the example 14 - 8 = 6. Using the subtraction table, we find in the table field a diagonal with a decreasing 14. In the figure below, this diagonal is highlighted in light green. We select the number 14 on this diagonal, which is opposite the subtracted 8. The resulting number 6 in the top row is the answer.

As you can see, the same addition and subtraction table is used for addition and subtraction, which you can print or download from the links above in different formats.

Subtraction table without answers print and download

Preparing for the game - settings

Any parameters and settings can be changed at any time, even during the game.
Initially the game is set up like this:
- Calculation type - Add up to 10
- Award 1- chocolate, premium 2- biscuit
- In game session 10 calculations (arithmetic examples)
- Percentage of examples that need to be solved correctly to receive Prize 1 - 90%
- Percentage of examples that need to be solved correctly to receive Prize 2 - 70%
You can choose any other type of calculation - depending on what the child knows and what is happening at school at the moment. Types of calculations in the game:
- Addition, subtraction, addition and subtraction (mixed):
  - To 10
  - up to 20 (with the transition through the ten)
  - Up to 20 (with and without the transition through the ten)
  - up to 30
  - Up to 100
- Multiplication, division or any combination -by 1, -by 2, -by 3.......etc. up to 10
- Number Comparison
Set how many examples will be in the game session. It is better to start with a small number of attempts - 5 or 10, so as not to discourage the child from continuing the game. When the child increases milk production :) improves performance, you can move on to a serious game with 100-200 examples.
Enter the percentage of correctly solved examples for which 1 and 2 awards are given. For starters, it is better to lower the percentage. For example, choose 70 and 50 percent for premiums 1 and 2, respectively. Later, the rates can be increased to 90 - 70. Or even up to 98% - 95% for absolutely terribly smart children :). Enter only numbers, without the % sign!
Write down the prizes that the child will receive for 1st and 2nd place.
The settings will be saved using a cookie (small script) and restored the next time you open the game page in your browser.

Now you can start the game!

To start the game, press the START button
When an example appears on the screen, the child must enter the answer after the "=" sign
If we play "comparisons", you need to enter the appropriate sign: . To do this, it is most convenient to use the buttons that will appear next to the NEXT button.
After the result is entered, you need to press the OK button (or ENTER on the keyboard) to check if the example was solved correctly.
If the example was solved correctly, "Correct" will appear on the screen. If not, "Incorrect" and the correct answer. At the same time, the game will calculate the percentage of correctly solved examples
To go to the next example, you need to click the NEXT button
When the session ends, the screen will display the prize that the child won (or "won nothing") and the percentage of examples correctly solved for the session
To start a new session, click the START OVER button.

Great expectations:)

What can you expect from this game? Great help in passing the school curriculum! As a rule, in 5-7 days, in which the child plays for 30-40 minutes, he firmly masters the next type of calculation (for example, adding up to 20 with a transition through the ten). And practically ceases to make mistakes in the classroom.

Addition table up to 20 print and download

Subtraction table up to 20 print and download

As you can see, the same addition and subtraction table is used for addition and subtraction, which you can print or download from the links above in different formats.

Subtraction table without answers print and download

In this lesson, you will learn how to add and subtract single-digit numbers with a jump through the digit. Solving interesting tasks, you will learn the algorithm for adding and subtracting numbers with the transition through a dozen and get acquainted with the addition table of single-digit numbers up to 20. You will have the opportunity to practice the previously studied material on interesting examples.

Topic:Introduction to basic concepts in mathematics

Lesson: Addition and subtraction of single-digit numbers with the transition through the category. Addition table up to 20

The graphical model can be used to explain addition of single-digit numbers with the transition through a dozen.

How can you add 9 and 7 together?(Fig. 1)

Rice. one

The graphical model shows that the first term 9 must be supplemented to 10. To do this, we divide the second term into two parts, one of which is equal to the number 1, since

9 + 1 = 10, so 7 = 1 + 6. (Fig. 2)

Rice. 2

Let's do the addition by parts:

9 + 7 = (9 + 1) + 6 = 10 + 6 = 16

Answer: 9 + 7 = 16.

You can add these numbers in a different way. (Fig. 3)

Rice. 3

The second term 7 can be supplemented to 10. To do this, we divide the first term into two parts, one of which is equal to the number 3. Therefore, 9 = 3 + 6.

Rice. 4

Let's do the addition by parts:

7 + 9 = (7 + 3) + 6 = 10 + 6 = 16

The first term is 9, it lacks up to 10 one unit, so we break the second term into parts. 5 is 1 and 4. We add to 9 first one unit, and then the remaining four units.

9 + 5 = 9 + (1 + 4) = 14

The first term is 6, it lacks up to 10 four units, so we divide the second term into parts: 4 and 2. We add 4 to 6 first and get ten units, and then the remaining two units.

6 + 6 = 6 + (4 + 2) = 12

The first term is 4, it lacks up to 10 six, so the second term 8 is divided into parts: 6 and 2. We add six units to 4 first and get ten units, and then the remaining two units.

4 + 8 = 4 + (6 + 2) = 12

In the reduced 15, there are five units, so we divide the subtracted 7 into parts: 5 and 2. We first subtract five units from 15, we get 10. Then we subtract the remaining two units from ten.

15 - 7 = 15 - (5 + 2) = 8

In the reduced 16, there are six units, so we divide the subtracted 9 into parts: 6 and 3. First subtract six units from 16, we get 10. And then subtract the remaining three units from 10.

16 - 9 = 16 - (6 + 3) = 7

In the reduced 12, there are two units, so we divide the subtracted 4 into parts: 2 and 2. Subtract 2 from 12, we get 10. And subtract 2 from 10.

12 - 4 = 12 - (2 + 2) = 8

Answer: 12 - 4 = 8.

It is not always convenient to use the method of addition and subtraction in parts with the transition through a dozen, so you need to learn single digit addition table up to 20 by heart.

The figure shows a table with which it will be easier for you to learn the cases of adding single-digit numbers up to 20. (Fig. 7)

Rice. 7

In each column, the first term is the same, and the second is increased by one, which means that the sum will also increase by one. Find the value of these sums.

9 + 2 \u003d 11, therefore: 9 + 3 \u003d 12, arguing like this, we fill out the entire table. (Fig. 8)

Rice. 8

Each line contains sums with the same answers. Choose the way it will be easier for you to remember the answers: in columns or in rows. If you learn well the table of addition of single digit numbers up to 20, then it will not be difficult for you to perform subtraction of single digit numbers within 20.

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