Fractional multiplication, fractional division, simple equation, observation object, polygon area, statistics and possibility, wide angle of mathematics, comprehensive application of mathematics.
People's education edition, fifth grade, first volume, mathematical concepts
The surface area of a cuboid = (length× width+length× height+width× height )× 2s = (AB+AH+BH )× 2.
Volume of cuboid = length× width× height V=abh
Surface area of cube = side length × side length× 6 s = 6a?
Volume of cube = side length × side length × side length V=a?
Volume of cuboid (or cube) = bottom area × height V=sh
The minimum multiple and maximum factor of a number is itself.
The number of factors of a number is limited.
The multiple of a number is infinite.
Among natural numbers, those that are multiples of 2 are called even numbers (0 is also even numbers), and those that are not multiples of 2 are called odd numbers.
Numbers in units of 0, 2, 4, 6 and 8 are all multiples of 2.
A number with 0 or 5 is a multiple of 5.
The sum of the numbers on each digit of a number is a multiple of 3, and this number is a multiple of 3.
If a number has only two factors: 1 and itself, it is called a prime number.
A number is called a composite number if it has other factors besides 1 and itself.
1 is neither prime nor composite.
The unit of volume is used to measure the volume. The commonly used unit of volume has cubic centimeters, cubic decimeters and cubic meters, which can be written as cm? ，dm？ And m? .
1dm？ = 1000cm？ 1m？ = 1000dm？
The volume that an object can hold is usually called its volume. Unit of volume is generally used to measure volume.
The volume of liquid is usually measured in liters and milliliters, and can also be written as L and ml.
1L = 1000ml 1L = 1dm？ 1ml= 1cm？
Fractions with numerator less than denominator are called true fractions. The true score is less than 1.
Fractions with numerator greater than denominator or numerator equal to denominator are called false fractions. False score is greater than or equal to 1.
The numerator and denominator of a fraction are multiplied or divided by the same number (except 0) at the same time, and the size of the fraction remains the same. This is called the basic nature of fractions.
Changing a fraction into an equal fraction with smaller numerator and denominator is called divisor.
Dividing the scores of different denominators by the scores of the same denominator equals the original score, which is called the total score.
Add and subtract fractions with the denominator, the denominator remains the same, and only the numerator is added and subtracted.
bonus
Dividends = —————
divisor
In a set of data, the number with the highest frequency is the pattern of this set of data.
In a set of data, there may or may not be multiple patterns.
1, distance, speed and time formula: s = vtv = s ÷ t t = s ÷ v.
2. Square perimeter formula: C=4a
3. Formula of square area: S=a2
4. Rectangular perimeter formula: C=2(a+b)
5. Rectangular area formula: S=ab
Additive commutative law: A+B = B+A.
7. Additive associative law: a+b+c=a+(b+c)
8. multiplicative commutative law: ab = b a.
9. Law of multiplication and association
10, multiplication and distribution law: [a+b] c = a c+b c.
1 1, classification of angles, from small to large: acute angle, right angle, obtuse angle, right angle and rounded corner.
12, acute angle less than 90 degrees, right angle 90 degrees, obtuse angle greater than 90 degrees but less than right angle, right angle 180 degrees, fillet 360 degrees.
13. Triangles are classified by angle: acute triangle, right triangle and obtuse triangle.
14. A triangle with three acute angles is called an acute triangle. A triangle with a right angle is called a right triangle; A triangle with an obtuse angle is called an obtuse triangle.
15. Triangles are divided into equilateral triangles, isosceles triangles and equilateral triangles.
16. Draw a vertical line from the vertex of the triangle to its opposite side. The line segment between the vertex and the vertical foot is called the height of the triangle, and the opposite side is called the bottom of the triangle.
17, the counting unit of decimals is one tenth, one hundredth, one thousandth -0. 1, 0.0 1, 0.00 1-
18. Properties of decimals: Add "0" or remove "0" at the end of decimals, and the size of decimals remains unchanged.
20. 1 angle =2 right angle 1 fillet =2 angle =4 right angle.
2 1, the triangle is stable.
22. The sum of any two sides of a triangle is greater than the third side.
23. The sum of the internal angles of a triangle is 180 degrees.
24. Learn to draw corners
25, will compare the size of decimals.
26, unit conversion
Unit of length: 1 m = 10 decimeter 1 decimeter = 10cm = 1 0mm10 decimeter =
Mass unit:1k g =1000g1t =1000kg =100000g.
Currency conversion: 1 yuan = 10 minute = 100 minute = 10 minute.
Time unit: 1 hour =60 minutes =3600 seconds 1 minute =60 seconds.
1 year = 65438+ February =365 days or 366 days 1 day =24 hours.
135780 wax, 3 1 day never goes bad. Four, six, nine, one, thirty, February 28th in a normal year and February 29th in a leap year.
Area unit: 1 m2 = 100 square decimeter 1 square decimeter = 100 square centimeter 1 m2 = 10000 square centimeter.
1 ha = 1 0000m21km2 =100ha =100000m2