Does anyone know the mathematical knowledge on clocks?
(1) The hour and minute hands overlap when they reach the hour, so they overlap 24 times in 24 hours a day. ,
The number of 90-degree angles is twice per hour, totaling 48 times
(2) The minute hand moves once, and the hour hand moves 1/12 times
Starting from 1 o'clock, the minute hand will coincide with the hour hand when it makes x circles
x = 1/12 + x/12 (the distance traveled by the minute hand = the position of the hour hand at 1 o'clock + the distance traveled)
11/12 x = 1/12
x = 1/11
The minute hand moves 1/11 times, which is 60/11 minutes
The knowledge and mathematics story of the year, month, and day that coincides with each other for the first time at 1:60/11 minutes
The knowledge points of "year, month, day" and "year" related knowledge: 1. One year = 12 Month and a half year = 6 months. Ordinary year = 365 days. Leap year = 366 days. 2. Judgment of ordinary years and leap years: Method: There is a leap every four years, there are no leaps in a hundred years, and there are leaps in four hundred years.
For example: 1968 - a leap year, 1954 - an ordinary year, 1900 - an ordinary year, 2000 - a leap year. Judgment method: If the last digit of the year is an odd number 1, 3, 5, 7, or 9, it must be an ordinary year, such as: 2011, 1985... If the last digit of the year is an even number, further judgment is required. There are two relatively simple methods: (1) Check whether the last two digits are divisible by 4, for example: 1928, the last two digits are 28÷4=7, so it is a leap year; another example: 1918, the last two digits are 18÷4=4...2, so it is an ordinary year.
(2) Remember that the special year 2000 is a leap year. Use the year to be judged to find the difference. For example: 1996, 2000-1996=4, 4 can be divided by 4 (it is a multiple of 4), so it is a leap year; another example: 2016, 2016-2000=16,16 Divisible by 4 (is a multiple of 4), so it is a leap year.
3. Calculate the anniversary: ??method: last year - initial year = anniversary. For example: October 1, 2011 is the (62nd) anniversary of the founding of the People's Republic of China. 2011-1949=62 (Anniversary) For example: June 8, 2012 is Xiao Ming’s 9th birthday. In what year was he born? 2012-9=2004 (year) Knowledge related to "month": 1. Big month = 31 days in the whole year *** There are 7 big months Small month = 30 days in the whole year *** There are 4 small months and a half Month = 15 days, February in a balance year = 28 days, February in a leap year = 29 days 2. Methods to determine the big month, small month, and leap month (February): (1) Fist memory method.