Four years later, 9-7=2 years old. The age problem in mathematics is named after the content of the topic. Its main feature is that the age difference between them is unchanged, but the multiple relationship of their ages changes with age. The answers to such questions need to grasp the rules, and parents can transfer them to their children.

Three basic characteristics

The age difference between two people is constant.

(2) The age of two people is increasing or decreasing at the same time.

(3) The multiples of two people's ages are changing.

Solution formula

The precession will not change, when adding and subtracting.

With the change of age, the multiple is also changing.

Grasp these three points and everything will be easy.

Ideas and methods to solve problems

1. can be used to solve the "differential multiple problems" ideas and methods.

2. The most basic questions about age are yesterday and today, one is the proportional method, and the other is the table equation method.

Example 1

Dad is 35 years old and Liang Liang is 5 years old. How old is Liang Liang this year? What about next year?

Solution: 35 ÷ 5 = 7 (times)

(35+ 1) ÷ (5+ 1) = 6 (times)

Dad is seven times as old as Liang Liang this year.

Dad will be six times as old as Liang Liang next year.

Example 2

Mother is 37 years old and daughter is 7 years old. In a few years, my mother will be four times as old as my daughter.

Solution: (1) How old is the mother than the daughter? 37-7 = 30 years old

(2) A few years later, the mother is four times as old as her daughter? 30(4- 1)-7 = 3 (year)

Column into a comprehensive formula (37-7) ÷ (4- 1)-7 = 3 (year).

A: After three years, the mother is four times as old as her daughter.

Show only a small part of talent

1.3 years ago, the father and son were 49 years old. This year, the father is four times as old as his son. How old are father and son this year?

2. A said to B, "My age is your present age, and you are 4 years old". Column into a comprehensive formula (37-7) ÷ (4- 1)-7 = 3 (year).

A: After three years, the mother is four times as old as her daughter.

Show only a small part of talent

1.3 years ago, the father and son were 49 years old. This year, the father is four times as old as his son. How old are father and son this year?

2. A said to B, "My age is your present age, and you are 4 years old".

B said to A, "When my age is your present age in the future, you will be 6 1 year old". What are the ages of Party A and Party B now? for reference only