First, the perimeter of primary school mathematical geometry
zone
Volume calculation formula
Perimeter of rectangle
=
(Dragon
+
Wide)
×
2 C =(a+b)× 1
2
The circumference of a square
=
Length of side
×
4 C=4a
Rectangular area
=
long
×
extensive
S=ab
Area of a square
=
Length of side
×
Length of side
a= a
Area of triangle
=
bottom
×
high
÷
2 S=ah
2
Area of parallelogram
=
bottom
×
high
S = ah
Trapezoidal area
=
(Upper bottom)
+
Bottom)
×
high
÷
2 seconds =
(
a
+
b
)
hú
2
diameter
=
radius
×
2 d=2r
radius
=
diameter
÷
2 r= d
2
perimeter of a circle
=
circumference ratio
×
diameter
=
circumference ratio
×
radius
×2 c=πd =2πr
Area of a circle
=
circumference ratio
×
radius
×
radius
Area of triangle = base
×
high
÷
2
formula
S= a×
hú
2
Area of a square = side length
×
Length of side
formula
S= a×
a
Area of rectangle = length
×
extensive
formula
S= a×
b
Area of parallelogram = base
×
high
formula
S= a×
h
Area of trapezoid = (upper bottom
+
Bottom)
×
high
÷
2
formula
S=(a+b)h
2
Sum of internal angles: sum of internal angles of triangle =
180
Degree.
Volume of cuboid = length
×
extensive
×
high
Formula:
V=abh
Volume of cuboid (or cube) = bottom area
×
high
Formula:
V=abh
Volume of cube = side length
×
edge
×
edge
Formula:
V=aaa
Circumference = diameter
×π
Formula:
L
=
πd
=
2πr
Area of circle = radius
×
radius
×π
Formula:
S
=
Pi?
r2
Surface (side) area of cylinder: The surface (side) area of cylinder is equal to the perimeter of bottom multiplied by height. Formula:
S=ch=πdh
=
2πrh
Surface area of cylinder: the surface area of cylinder is equal to the perimeter of the bottom multiplied by the height plus the area of the circles at both ends.
Formula:
S=ch+2s=ch+2πr2
Volume of cylinder: the volume of cylinder is equal to the bottom area multiplied by the height. Formula:
V=Sh
The volume of the cone =
1/3
the seamy side
×
Cumulative height formula:
V= 1/3Sh
Fractions add up,
Reduction rules:
Add and subtract fractions with the same denominator,
Only add and subtract molecules,
The denominator remains the same.
Fractions of different denominators are added and subtracted,
Go too far first,
Then add and subtract.
The multiplication of fractions is: use the product of molecules as numerator and the product of denominator as denominator.
The law of division of fractions: dividing by a number is equal to multiplying the reciprocal of this number.
Second, the unit conversion
(
1
)
1
Kilometers =
1
kilometre (km)
1
Kilometer =
1000
rice
1
M =
10
decimetre
1
Decimeter =
10
centimetre
1
Cm =
10
millimetre
(
2
)
1
Square meters =
100
Square DM
1
Square decimeter =
100
Square centimeter
1
Square centimeter =
100
square millimeter
(
three
)
1
Cubic meters =
1000
cubic decimeter
1
Cubic decimeter =
1000
cubic centimeter
1
Cubic centimeter =
1000
cubic millimeter
(
four
)
1
Ton =
1000
kilogram
1
kilogram
= 1000
Scold or fight?
= 1
kilogram
= 2
gold
(
five
)
1
Hectares =
10000
square meter
1
Mu =
666.666
square meter
(
six
)
1
L =
1
Cubic decimeter =
1000
millilitre
1
ML =
1
cubic centimeter
(
seven
)
1
Yuan dynasty (1206- 1368)
= 10
corner
1
corner
= 10
minute
1
Yuan dynasty (1206- 1368)
= 100
minute
(
eight
)
1
hundred years
= 100
year
1
year
= 12
moon
A bigger month
(3 1
sky
)
have
: 1\3\5\7\8\ 10\ 12
moon
The 29-day month of the lunar calendar
(30
sky
)
Yes
:4\6\9\ 1 1
moon
Average year (as opposed to leap year)
2
moon
28
sky
,
leap year
2
moon
29
sky
Average year and whole year
365
sky
,
leap year
366
sky
1
sun
=24
hour
1
time
=60
minute
1
minute
=60
second
1
time
=3600
second
Third, the calculation formula of quantitative relationship
1
, per share
×
Number of copies = total number
total
÷
Number of copies = total number of copies
÷
Number of copies = number of copies
2
、
1
multiple
×
Multiple = multiple
several times
÷
1
Multiple = multiple. How many times?
÷
Multiplication =
1
multiple
three
, speed
×
Time = distance
Travel distance
÷
Speed = time
Travel distance
÷
Time = speed
four
unit price
×
Quantity = total price
total
÷
Unit price = quantity
total
÷
Quantity = unit price
five
, work efficiency
×
Working hours = total amount of work
Total workload
÷
Work efficiency = the total amount of work during working hours
÷
Working hours = working efficiency
six
Appendix+Appendix = Sum
And-one addend = another addend
seven
, minuend-minuend = difference
Negative difference = negative
Difference+Minus = Minus
eight
, factor
×
Factor = product
gather
÷
One factor = another factor
nine
dividend
÷
Divider = quotient
bonus
÷
Quotient = divisor
business
×
Divider = dividend
Fourth, arithmetic.
1
Additive commutative law: Two numbers are added to exchange the position of the addend, and the sum remains the same.
2
Law of addition and combination: when adding three numbers, add the first two numbers, or add the last two numbers first, and then be the same as the first number.
Three numbers add up, and the sum remains the same.
three
Multiplication and exchange law: when two numbers are multiplied, the position of the exchange factor and the product remain unchanged.
four
Multiplication and association law: when three numbers are multiplied, the first two numbers are multiplied, or the last two numbers are multiplied first and then the third number is multiplied.
The product remains unchanged.
five
Multiplication and distribution law: when two numbers are multiplied by the same number, you can multiply the two addends by this number respectively, and then add the two products to form a knot.
The fruit remains the same. For example:
(
2+4
)
×
five
=
2×
5+4×
five
six
The essence of division: in division, the dividend and divisor are expanded (or reduced) by the same multiple at the same time, and the quotient remains unchanged.
Separated by anything that is not.
You must have all the figures.
seven
Equation: An equation in which the value on the left of the equal sign equals the value on the right of the equal sign is called an equation. The basic property of the equation: both sides of the equation are multiplied at the same time
Divided by the same number, this equation still holds.
eight
Equation: An equation with an unknown number is called an equation.
nine
One-dimensional linear equation: contains an unknown number and the number of times of the unknown number.
One of the equations whose number is once is called a linear equation with one variable.
Example method and calculation of learning linear equation of one variable. There are examples.
χ
Formulas and calculations.
10
Score: put the unit
" 1"
Divide into several parts on average, and the number representing such a part or a few points is called a score.
1 1
Addition and subtraction of fractions: add and subtract fractions with the same denominator, only add and subtract numerators, and the denominator remains the same. Fractions of different denominators are added, subtracted and added first.
Divide, then add and subtract.
12
Comparison of fraction size: Compared with the fraction of denominator, the numerator is large and the numerator is small. First, compare and divide the scores of different denominators.
Then compare; If the numerator is the same, the denominator is big and small.
13
Fraction multiplied by integer, numerator is the product of fractional and integer multiplication, denominator remains unchanged.
14
Fractions are multiplied by fractions, the product of numerator multiplication is numerator, and the product of denominator multiplication is denominator.
15
. Fraction divided by integer (
Except)
, equal to the fraction times the reciprocal of this integer.
16
True fraction: The fraction with numerator less than denominator is called true fraction.
17
False fraction: Fractions with numerator greater than denominator or numerator equal to denominator are called false fractions. Error score greater than or equal to
1
18
Using fraction: writing a false fraction in the form of integer and true fraction is called using fraction.
19
The basic nature of a fraction: the numerator and denominator of a fraction are multiplied or divided by the same number at the same time (
Except)
, the size of the score remains unchanged.
20
A number divided by a fraction is equal to the number multiplied by the reciprocal of the fraction.
2 1
. A number divided by b number (
Except)
, equal to the reciprocal of a multiplied by b.
Verb (abbreviation of verb) special problems
Formula of sum and difference problem
(
Sum+difference
)
÷
2
= large number
(
And poor
)
÷
2
= Decimal
And folding problems.
Heao
(
Multiple-
1)
= Decimal
Decimal × multiple = large number
(
or
Sum-Decimal = large number
)
Difference problem
Chaao
(
Multiple-
1)
= Decimal
Decimal × multiple = large number
(
or
Decimal+difference = large number
)
Tree planting problem