When it comes to the relationship between numbers, many students are very old, especially those who are not good at math. They get dizzy easily when they see numbers, let alone work out the correct answers quickly. Today, I will share the skills of five types of questions, hoping to help everyone.

1, sum times problem

Problem description: Knowing the relationship between the sum and multiple of two numbers, we can get these two numbers quickly.

Spike formula: big+small = sum; Large = times × small, then: small = and present (times+1); Big = times × small = and-small.

2. The problem of time difference.

Problem description: Knowing the difference and multiple relationship between two numbers, we can get these two numbers quickly.

Spike formula: big-small = poor; Large = times × small, then: small = poor ÷ (times-1); Big = times × small = difference+small.

3. Sum and difference problem

Problem description: If you know the sum and difference of two numbers, you can get them quickly.

Spike formula: big+small = sum; Big-small = poor; Then: big = (sum+difference) ÷ 2; Small = (sum and difference) ÷2

4, the date problem

Problem description: If it is Wednesday of July 17, what day is August 18?

Second kill formula: average year: 365=52×7+ 1, even number1; Leap year: 366=52×7+2 across 2.

5. Plant trees

Problem description: When planting trees in a road section, the relationship between the number of trees and the number of road sections is different and in different ways.

Ear formula: ① unsealed road section: planting at both ends: number of plants = number of segments+1; Planting at one end: number of plants = number of segments; ② No planting at both ends: number of plants = number of segments-1; ③ Closed route: number of trees = number of segments.

The above is the number of seconds kill skills taught to everyone. Is it very simple? In fact, the number of questions is not difficult. As long as you master the method and remember the spike formula, you will save time and effort.