B1 - (two digit number) + (two digit number)
B2 - (two digits) - (two digits)
B3 - Addition and subtraction of three-digit numbers
B4 - Applications of addition and subtraction
B5 - Multiplication
B6 - Multiplication Tables
B7 - Division
B8 - Applications of Multiplication and Division

Soma Sem's method of learning operations

① Single-digit addition of numbers greater than 10
The basis of addition and subtraction is counting.
The important concept is that 8+4 is 8 plus 1 four times.
If you think about carrying using 10's complement, 8+4 is (8+2)+2, but it is better to stick to the basic concept of addition when starting to study operations.
This book provides concrete examples and calculations to help you understand the concepts through concrete objects.

② Horizontal calculation
Vertical arithmetic is not a wrong method, but if you forget the principles of calculation and only remember where to write the number you carry over, thinking of it as a formula and repeating it mechanically, you will end up doing vertical arithmetic without thinking.
However, the ability to think about numbers, which can be developed through thinking about principles through cross-sectioning and dividing and pasting numbers, is also very important.

③ Multiplication table
If you focus only on memorizing multiplication tables, there will be significant side effects.
You should learn to memorize the multiplication tables based on the understanding that multiplication is a compressed version of addition, and that this will allow you to perform calculations quickly.
Although memorizing multiplication tables is important, knowing the exact meaning of multiplication is more important.
We must ensure that students who know how to do 4×3 do not claim that they cannot do 45×3 because they did not learn how to multiply two digits by one digit.


The reality of computational education

The biggest drawback to arithmetic education is the distorted marketing of existing arithmetic workbooks, such as "If you're not fast at arithmetic in the upper grades of elementary school, you'll struggle," and the emphasis on rote arithmetic through simple repetition.
However, computations that focus on mechanical repetition not only make children hate math, but also hinder the expansion of thinking through computational learning that lacks concepts and principles.


Elementary Mathematics Curriculum and Operations

In the elementary education curriculum, we explain things verbally without using letters and symbols while remaining faithful to the concepts and principles of operations, and from the secondary education curriculum onwards, letters and symbols are used.
If you look at the textbook, the principles are well explained in the introduction of all operations.
In reality, descriptive questions that ask about the principles of calculations are also given, but the prevailing perception is that practice is the priority in calculations.

How about computational learning?

Arithmetic education should never be done in isolation, using only abstract numbers or symbols.
It requires practice after thinking and understanding with concrete objects.
Additionally, you should focus on developing good habits that will help you overcome mistakes, with an emphasis on accuracy rather than speed.