Teaching mathematics to elementary school students in a simple and engaging way for children, making it easy for them to acquire information and knowledge. We will determine the necessary lesson to explain. For example, the lesson on even and odd numbers: even numbers are 2, 4, 6, 8, and 10, and odd numbers are 1, 3, 5, 7, and 9. Similarly, the lesson on rounding: we need to know the generous numbers (5, 6, 7, 8, and 9) and the stingy numbers (1, 2, 3, and 4) and solve rounding problems. For example... 25 is approximately 30, and 21 is approximately 20.

To solve the problem 123 + 546, add the ones with the ones, the tens with the tens, and the hundreds with the hundred, resulting in 669. When subtracting, 987 - 754 = 233. When solving problems, 268 + 324 = 5. When adding the ones and the ones, we write the ones and find the tens, which is 2. We add 1 to the tens, which is 6, making 7. We add this to 2, which is 9. We continue adding, 2 + 3 = 5. The total result is 592.