Mathematics in the first semester of the sixth grade

The unit "1" is known: The unit "1" corresponds to the fraction = the corresponding quantity.

Finding the unit "1" or the unit "1" is unknown: Corresponding Quantity Corresponding Fraction = Unit "1".

Find the formula for how many fractions (or hundredths) of one number is another number:

One number Another number = A number is a fraction (or hundredth) of another number

Find the formula for how many fractions (or hundredths) of a number is more than another:

The number of units "1" = a fraction (or hundredth) of a number more than another

Find the formula for how many fractions (or hundredths) of a number is less than another:

Quantity less unit "1" = a fraction (or hundredth) of a number less than another

Note: "more" and "less" here can also be replaced with words such as "increase production" and "save". ）

Note: Example: (1) There are 120 peach trees in the orchard, and the number of pear trees is 20% more than that of peach trees, how many pear trees are there in the orchard?

2) There are 120 peach trees in the orchard, which is 20% less than the number of pear trees, how many pear trees are there in the orchard?

Analysis idea: first find out the unit "1", determine whether it is known or unknown, the unit "1" knows to use multiplication, and the unit "1" does not know to use division. The column formula "more (less) fractions than whom" is "1+(-fractions)". ）

Column: (1)120 (1+20%)

Discount, Profit, Interest, Tax application problem solving formula.

Meaning: The meaning of "20% off" is: the current price is 80% of the original price; The meaning of "85% off" is: the current price is 85% of the original price

Formula: Current Price = Original Price Discount (usually written as a percentage).

Profit = Selling Price - Cost.

Interest = Principal Interest Rate Time.

After-tax interest = principal interest rate time 80% (note: national debt and education savings are not taxable).

Tax payable = money subject to tax rate.

Formulas and key statements for the circumference and area of a circle.

The ratio of the circumference of a circle to the ratio of its diameter is called pi. π= c ÷ d

Find the perimeter of the known diameter: c = d Find the diameter of the known perimeter: d = c

Find the perimeter of the known radius: c = 2 r Find the radius of the known perimeter: r = c 2

Find the area of the known radius: s = r

Find the area of the known diameter: r = d 2

s = πr

Find the area of the known perimeter: r = c 2

s = πr

Circumference of the Half Circle = C2 + D (Note: Circumference of the Half Circle = for fill-in-the-blank questions).

Semicircular area = s 2

Divide a circle into equal parts and put together an approximate rectangle. (See book).

1) The area of the rectangle = the area of the circle.

2) The length of the rectangle = half the circumference of the circle (length = ).

3) The width of the rectangle = the radius of the circle (width = r).

4) The circumference of the assembled rectangle is 2r (or d) more than the circumference of the circle

There are three main categories of math formulas for Primary 6:

1. Letters are used to represent the laws or properties of operations (commutative laws, associative laws, and distribution rates).

2. Geometric calculation formulas (perimeter, area, surface area and volume).

3. Quantity relationship (basic quantity relationship, encounter problem, discount problem, catch-up problem, etc.).

The specific formulas are:Commutative law of addition: a+b b+a;

Additive associative property: (a+b)+c a+(b+c);

Commutative law of multiplication: ab=ba;

Multiplicative associativity: (ab)c=a(bc);

Multiplicative distributive property: a(b+c) ab+ac.

Rectangle circumference = (length + width) 2;

Square circumference = side length 4;

Circumference of the circle = pi diameter = pi radius 2.

The area of the rectangle = length and width;

The area of the square = the length of the side The length of the side;

Area of the parallelogram = base height;

Area of the triangle = base height 2;

The area of the trapezoid = (upper bottom + lower bottom) height 2;

Area of the circle = pi radius;

Annular area = outer circle area Inner circle area;

Surface area of the box = (length and width + length and height + width and height) 2;

The surface area of the cube = edge length Ridge length 6;

The side area of the cylinder = the height of the bottom circumference;

Surface area of the cylinder = side area + base area 2;

The volume of the box = length, width, height;

The volume of the cube = edge length edge length edge length;

The volume of the cylinder = the base area is high;

The volume of the cone = the base area is 3 high.

Average = Total Total Number of Copies;

Average speed = total distance total time;

Encounter distance speed and encounter time, encounter time encounter distance speed and;

Discount Current Original Price (Discount 1), Current Original Price Discount, Original Price = Current Price Discount;

Scale bar = distance on the graph actual distance, actual distance = distance on the graph scale, distance on the graph = actual distance scale;

Chase distance Speed difference Chase time, chase time chase distance Speed difference.

It is a mathematical formula, not a mathematical formula, and you must not make a typo, and you must develop good habits.

Too much. Didn't have time to write that much.

s circle = * r 2 c circle = *d

Concentration = mass of solute mass of all liquids.

There aren't too many formulas, mainly equations and inequalities under six.