Math Math has several math modes

There are three kinds of them. Arithmetic cards, students are very fond of using flashcards for arithmetic training. The app offers even better arithmetic cards, which can be scribbled on the cards and made them bigger or smaller.

The math problems provided by the arithmetic cards are very personalized. For example: picking the largest number, the smallest number, arithmetic, or questions about negative numbers and decimal points. Flashcards focus on developing memory and helping children improve their ability to retrieve information.

Bingo Mathematics exercises children's ability to solve problems through mathematical logical thinking.

Bubble arithmetic, different from simple arithmetic problems. It asks children to think about how to use addition or multiplication to get a number.

To do the problem, one type at a time to solve slowly, especially to solve a problem, a special sense of achievement, especially want to learn.

Although I didn't go to high school or college, I was mostly in the top 5 in mathematics from elementary school to junior high school. Mathematics is not difficult to learn, the key is to have logical performance and understanding, what is the use of you doing 10,000 questions without understanding.

Listen carefully in class and read books after class.

Memorize formulas, apply them flexibly, and do more questions.

Arithmetic mean: Divide the sum of n numbers by n, and the resulting quotient is called the mean of these n numbers geometric mean: Formula:

x=(x1*x2*..xn) (1 n) harmonic mean: formula:

n/(1/a1+1/a2+..1 an) Weighted Average: Formula:

x1f1 + x2f2+ .xkfk) n square mean: formula:

m=[(a^2+b^2+c^2+…n^2)/n] ^1/2)。

Index averages.

Weighted arithmetic mean, arithmetic mean x=(x1+x2+x3...).xn) n weighted average y=(a1*x1+a2*x2+a3*x3...an*xn)

a1+a2+a3...an=1

AI is the right. The weighted average can also be expressed as:

y=(a1*x1+a2*x2+a3*x3...an*xn)/ba1+a2+a3...an=b

Harmonic mean< = geometric mean< = arithmetic mean< = square mean.

Arithmetic mean.

The arithmetic mean is the sum of all the data in a set of data divided by the number of data. It is a metric that reflects trends in a data set.

The formula is: average = (a1 + a2 + ...+an)/n

For example, the average of 3,4,5 is:

Geometric mean.

geometric

The nth arithmetic root of the product of a positive real number of meann. Given n positive real numbers.

a1,a2,…, an, whose geometric mean is (a1*a2*......an)^(1/n).In particular, the geometric mean c (a*b) (1 2) of the two positive numbers a,b is the middle term in the ratio of a to b. The geometric mean of any n positive numbers a1, a2, and an is not greater than the arithmetic mean of these n numbers, i.e., (a1*a2*......an)^(1/n)≤（a1＋a2＋…＋an）/n

This inequality is often useful in the study of other inequalities or extreme values.

Reconcile averages.

Harmonic Mean (harmonic

mean) is a type of average. However, the statistical harmonic mean is not the same as the mathematical harmonic mean. In mathematics, harmonic mean and arithmetic mean are independent and self-contained.

The results are not the same, and the former is always less than the latter. Thus the mathematically harmonized mean is defined as: the reciprocal of the mean of the reciprocal of the numerical reciprocal.

However, the statistically weighted harmonic mean is different in that it is a deformation of the weighted arithmetic mean, which is attached to the arithmetic mean and cannot be established as a separate system. And the result is exactly equal to the weighted arithmetic mean. It is mainly used to solve the problem that the overall number of units (frequency) cannot be grasped, only the value of the variable and the corresponding total number of flags of each group, and the average number needs to be obtained.

The formula is: 2 (a +1 b).

Weighted average.

If n number x1, x2 ,......The weights of xn are w1, w2, ,......wn, then the weighted average of these n numbers is (x1w1+x2w2+......xnwn)/(w1+w2+……wn)

Note: 1) The English word for "right" is weight, which indicates the importance of the data. That is, the power of the data reflects the relative "importance" of the data

2) The arithmetic mean is a special case of the weighted average, that is, when the weights of the items are equal, the weighted average is the arithmetic mean.

Square mean.

The formula is: m=[(a 2 + b 2 + c 2 + ...n^2)/n]^½

The so-called mathematical thought refers to the results of the reflection of the spatial form and quantitative relationship of the real world into people's consciousness through thinking activities. Mathematical thought is the essential understanding of mathematical facts and theories after generalization. Basic mathematical ideas are the foundational, summative and most extensive mathematical ideas that embody or should be embodied in basic mathematics, which contain the essence of traditional mathematical ideas and the basic characteristics of modern mathematical thoughts, and are developing historically.

1.Function Idea:

Represent a mathematical problem as a function, and use the general law of the function ** problem. This is the most basic and commonly used mathematical method.

2.The idea of combining numbers and shapes:

Combining algebra and geometry, e.g. algebraic solutions to geometric problems and geometric solutions to algebraic problems, is most commonly used in analytic geometry. For example, if you find the minimum value of the root number ((a-1) 2+(b-1) 2) + the root number (a 2+(b-1) 2) + the root number ((a-1) 2+b 2) + the root number (a 2+b 2), you can put it in the coordinate system and convert it into a point to the distance from (0,1), (1,0), (0,0), (1,1) to the four points, and then you can find its minimum value.

3.Categorical discussion ideas:

When a problem may cause different results due to the different situations of a certain quantity, it is necessary to classify and discuss the various situations of this quantity. For example, solving inequalities|a-1|>4, we need to discuss the value of a.

4.Equation Thought:

When a problem is likely to be related to an equation, the equation can be constructed and the properties of the equation can be studied to solve the problem. For example, when proving Cauchy's inequality, you can transform Cauchy's inequality into a discriminant of a quadratic equation.

In addition, there are mathematical ideas such as inductive analogy, transformational induction, probability and statistics, etc., for example, using inductive analogy ideas can be used to study some similar problems and get their commonalities, so as to derive general methods to solve these problems. Transforming inductive thinking is the transformation of a more complex problem into another simpler problem and the generalization of its methods. The idea of probability and statistics refers to solving some practical problems through probability statistics, such as the winning rate of the lottery, the comprehensive analysis of a certain exam, and so on.

In addition, some area problems can be solved using probabilistic methods.

In addition, the mathematical method is neither a ability nor a method, but it is used to guide the method.

The idea is extracted and summarized from the process of some specific mathematical cognition, and its correctness has been repeatedly confirmed in subsequent cognitive activities, with general significance and relatively stable characteristics. For example, Karl formulated analytic geometry, Napp formulated logarithms, and Lybnitz and Newton formulated calculus.

Including: Symbolic Ideas, Analogy Ideas, Classification Ideas, Equation and Function Ideas, and Modeling Ideas.

Choose answer C, and everything else can be folded into the same rectangle.

If the angle BCE=30°, the EH is perpendicular to H

Let ec=xeh= ch= 3 2x bh=eh sinb=3 8x3 8x+ 3 2x=3 x=(32 3-24) 13 if the angle ace=30° as eh vertical ac at h

Let ec=xeh= ch= 3 2x ah=eh sina=2 3x2 3x+ 3 2x=4 x=(72 3-96)11ce=32 3-24) 13 or =(72 3-96)11

Rational numbers can be divided into integers and fractions can also be divided into positive rational numbers, 0, negative rational numbers. Real numbers other than infinite non-cyclic decimals are collectively referred to as rational numbers. English:

Rational number pronunciation: yǒu lǐ shù integers and fractions are collectively referred to as rational numbers, and any rational number can be written as fractions m n (m, n are integers, and n ≠0). Any rational number can be represented on a number line.

These include integers and what is commonly referred to as a fraction, which can also be expressed as a finite decimal or an infinite loop decimal. This definition applies to both decimal and other carry systems of numbers, such as binary. Mathematically, a rational number is a ratio of an integer a to a non-zero integer b, usually written as a b, so it is also called a fraction.

The Greek word "originally meant "rational number", but the Chinese translation was inappropriate and gradually became "reasonable number". Infinite non-cyclic decimal numbers are called irrational numbers (e.g., pi), and rational numbers and irrational numbers are collectively called real numbers.

The set of all rational numbers is represented as q. The following are all rational numbers: (1) Integer:

Positive integers, 0s, and negative integers are collectively referred to as integers.

2) Scores: Positive scores and negative scores are collectively referred to as scores.

3) Finite decimals: decimals, finite cyclic decimals.

Remember: infinite non-cyclic decimal numbers are not rational numbers; It is an irrational number.

Irrational numbers and rational numbers are collectively referred to as real numbers.

Rational numbers are divided into: positive, 0, and negative.

Positive numbers are divided into: positive integers and positive fractions.

Negative numbers are divided into: negative integers and negative fractions.

Rational numbers are divided into: integers, 0, and fractions.

Integers are divided into: positive integers and negative integers.

Scores are divided into: positive and negative.

Real Number = Integer + Fraction = Positive Number + Zero + Negative Number = Rational Number + Irrational Number Rational numbers are to be divided into positive and negative, of course, 0 and infinite cyclic decimal numbers should also include....In the range of real numbers, except for infinite non-cyclic decimals, the others are rational numbers complex = real number + imaginary number .

Positive, negative, 0, finite cyclic decimals.

Irrational number: An infinite non-cyclic decimals. Such as: