1, carry and borrow: In addition and subtraction, carry and borrow are common situations. Carry means that when the sum or difference of a bit is greater than or equal to 10, it goes to the high position of 1. Borrowing means borrowing 1 from the high position if the minuend is less than the minuend in subtraction. These two skills should be paid attention to in the calculation process.
2. Estimation: When dealing with large numbers, you can estimate the sum or difference of each bit first, and then make an accurate calculation. This can reduce the chance of misjudgment.
3. Column Vertical: For complex addition and subtraction operations, the calculation process can be listed vertically, which is clearer and easier to operate.
4. Digit grouping: when adding or subtracting multiple digits, it can be grouped by digits, which is convenient for bit-by-bit calculation.
Calculation method of addition and subtraction:
Addition refers to the process of adding two or more values to get a total. Align two or more addends from right to left, one digit, ten digits, and so on. Start from a little bit and increase bit by bit. If the sum of one bit is greater than or equal to 10, carry it to the high bit. Repeat the above steps until all the figures add up.
Subtraction means subtracting one number from another to get a business trip. Align the minuend and subtree from right to left, one bit alignment, ten bit alignment, and so on. Subtract one bit at a time. If the minuend of a bit is less than the minuend, borrow from the high bit. Repeat the above steps until all the figures are subtracted.
Importance of addition and subtraction:
Addition and subtraction operations are one of the most basic operations in mathematics, and they constitute the cornerstone of mathematical operations. They are widely used, not only in the field of mathematics, but also in various life and work scenes, such as calculating the total price when shopping, measuring the length and weight of objects, calculating the length of time and so on.
Learning addition and subtraction is helpful to cultivate children's logical thinking ability, calculation ability and ability to solve practical problems. Secondly, addition and subtraction laid a solid foundation for the subsequent study of other mathematical knowledge.
In the process of learning mathematics, we will come into contact with more complicated operations, such as multiplication, division, fraction, algebra and so on. Addition and subtraction, as the most basic operation, is the premise of understanding and mastering these advanced mathematical concepts. If you don't master addition and subtraction, subsequent learning will become difficult.