Who has a calculator for time addition and subtraction? Find a calculator that can calculate the time addition and subtraction method, for example: it's 13:57 now, work out what time is 11 hours and 29 minutes later

Who has a calculator for time addition and subtraction? Find a calculator that can calculate the time addition and subtraction method, for example: it's 13:57 now, work out what time is 11 hours and 29 minutes later

General scientific calculators are OK, and Casio's is not expensive. They are generally 10 base systems, but they can be adjusted to calculate the angle in one place. When calculating the angle, the accounting time is the same. They are all 60 base systems, so we can use the method of calculating the angle to calculate the time

Why can't I use the addition and subtraction method to solve some problems with hours or time? Please help me find more questions of this kind
For example, the assignment left 213 to 218 pages, which should be 6 pages, but why 218-213 = 5? Let's talk about the characteristics of this kind of problem.
What kind of questions is this kind of questions generally applied to, such as quadratic function questions, statistical probability or geometry

Can be calculated with the addition and subtraction method!
For example, how many numbers are there in the sequence 4,5,6,..., 100?
(100-4) + 1 = 97
Similarly, your part: (218-213) + 1 = 6 (page)
Note: because the 213 you subtract does not include itself
Another different example,
Today is May 6th. How many days are there from May 20th to May 20th?
（1）（20－6）+1＝25
（2）20－6＝14

When to use addition, subtraction and elimination method for binary linear equation

When the coefficients of an unknown number (such as x) are the same, subtraction is used; when they are opposite, addition is used

There is a system of equations. If we use the method of addition, subtraction and elimination, then under what circumstances do we use the method of addition and subtraction?

The coefficients of the same unknowns are expanded by multiple, and the coefficients are 0 by addition and subtraction. The equations can be solved by addition and subtraction elimination method