Basic rules of addition and subtraction by a column

Column addition and subtraction are rarely difficult, even for elementary school students. However, when it comes to adults, in many cases they are so used to using technology that they even forget something so simple. This is even taking into account the fact that addition and subtraction are carried out by a column in grade 2. In any case, this article will help you remember everything. It is also useful to those who need to explain material on addition and subtraction by a column to children. However, it is even easier for children.

The mathematical "skeleton" of the number

Before learning to follow the examples of addition and subtraction by a column, make sure that you remember the material presented in this picture as an example of the number 80783023.

Visual explanation of the principle of addition by a column

Carefully study how the example 157 + 358 = 515 was resolved.

As you can see, the addition by a column is carried out alternately first with units of numbers, then with their tens, hundreds, thousands and so on. Let us consider in more detail what is shown in the picture.

At the first stage, the units of numbers 157 and 358 are added up. Accordingly, you need to add 7 and 8 by oral count, which will be 15. After that, you need to write down the units of the resulting number under the addition line (for number 15 it is 5), and remember dozens of it. At the second stage, dozens are added, and for given numbers, tens are numbers 5 and 5. The result of their addition will be 10. "So, under the addition line you need to write 0", which is a mistake many make. In fact, to this number you need to add the unit that remains from the number 15. This is because for the number 15 1 - its ten, like that class of numbers, the addition process of which is happening right now. Thus, under the addition line, you need to write the number 1. Again, you need to remember the number 1, since it is the ten of the resulting number 11. And in the third stage, after adding 1 and 3, it turns out 4, and the same unit is added to this sum, forming the number of hundreds 5. Thus, any natural numbers can be added. As for the subtraction by the column, addition, in fact, is the inverse of the process. Therefore, it is performed in the same way.

Column addition and subtraction examples (Grade 2)

Try to solve the following column addition examples:

1. 374 + 91 =
2. 4862 + 57834 =
3. 1784 + 467 =

You can check yourself either with the help of a calculator, or by these answers:

1. 465
2. 62696
3. 2251

Now you can try to apply your knowledge in the following subtraction examples:

1. 6475 - 1763 =
2. 487673 - 466556 =
3. 756 - 364 =

And here are the answers:

1. 4712
2. 21117
3. 392

Now you can confidently solve the addition and subtraction column examples.