1. Sum problem: The odd-even combination formula can be used to solve the sum of a series of numbers, especially when these numbers are odd and even. For example, to solve the sum of 1+3+5+7+9, we can convert it into the form of (1+9)+(3+7)+(5), and then calculate the sum in each bracket separately, and the result is 25.
2. Multiplication problem: The odd-even combination formula can also be used to solve the product of a series of numbers, especially when these numbers appear alternately. For example, to solve the product of 2*4*6*8* 10, we can convert it into the form of (2* 10)*(4*8), and then calculate the product in each bracket separately, and the result is 3840.
3. Average problem: Even-odd combination formula can also be used to solve the average of a series of numbers, especially when these numbers appear alternately. For example, to find the average value of 1+3+5+7+9, we can convert it into the form of (1+9)/2, and then calculate the result as 5.
4. Maximum common divisor and minimum common multiple: the odd-even combination formula can also be used to solve the maximum common divisor and minimum common multiple of two numbers. For example, to find the greatest common divisor of 12 and 16, we can convert it into the form of (12*2)/4 and (16/2), and then calculate the values in each bracket respectively, and the result is 4.
Generally speaking, the odd-even combination formula is a very practical mathematical skill, which can help us solve the problems related to odd-even numbers more quickly and accurately.