1. Basic Law
In the multiplication table of nine, the single digits of multiples of nine are increasing and the ten digits are decreasing. For example, 9 times 1 equals 9, 9 times 2 equals 18, 9 times 3 equals 27, and so on. This law applies to all multiples of 9, from 9 times 1 to 9 times 9.
2. Derivation method
The multiplication table of nine can be deduced mathematically. Take the single digits in the nine multiplication table as an example. The result of multiplying nine by any single digit can be written in the form of two digits. The single digit part is the single digit of the product, and the ten digit part is the single digit plus 1. For example, 9 times 1 equals 9, which can be written as 09, and 9 times 2 equals 18, which can be written as 1 (single digit+1)8. Through this derivation method, the law of single digits in the multiplication table of nine can be obtained.
3. Application example
Nine multiplication formulas are widely used in daily life and study. First of all, the multiplication table of nine can help students calculate the multiple of nine quickly and accurately, and improve the calculation efficiency. Secondly, the multiplication formula of nine can also be used to solve some practical problems, such as calculating discounts and concessions when shopping and changing the calculation time.
In addition, the multiplication table of nine can also be used to cultivate students' mathematical thinking and logical reasoning ability, and the multiplication table of nine can be deduced by observing and discovering the law.
Clever use of skills
When using the multiplication table of nine, you can also use some clever techniques to simplify the calculation. For example, when 9 is multiplied by a two-digit number, you can first add this digit to 1, then multiply the ten digits by this digit, then multiply this digit by 10, and finally add the two results. This technique is helpful to simplify the calculation process and reduce the occurrence of errors.
In addition, the rules in the multiplication table of nine can be used to simplify the calculation into addition and subtraction of single digits, thus further improving the calculation efficiency.
abstract
The multiplication table of nine refers to the calculation method and result of the multiple of nine in the multiplication table of nine. The law of the multiplication table of nine is that single digits increase and ten digits decrease. The multiplication table of nine can be deduced mathematically, which can help students calculate the multiple of nine quickly and accurately.
Nine multiplication tables are widely used in daily life and study, which can be used to solve practical problems and cultivate mathematical thinking ability. When using the multiplication table of nine, some clever skills can be used to simplify the calculation process and improve the calculation efficiency.