2. Determine how to calculate each step, list formulas and work out numbers; 3. Test and write the answers. (XIX) Enumerate the equation 1 the general steps to solve application problems. Find out the meaning of the problem, find out the unknown, and express it with X; 2. Find out the equal relationship between quantity and quantity in the application problem and make the equation; 3. Solve the equation; 4. Test and write the answers. (20) The addition and subtraction law of the denominator fraction is the same as that of the denominator fraction, and only the numerator is added and subtracted. (21) Addition and subtraction of fractions with the same denominator Using fractional addition and subtraction, the integer part and the decimal part are added and subtracted respectively, and then the obtained numbers are combined. (twenty-two) the addition and subtraction of different denominator fractions, the addition and subtraction of different denominator fractions, first calculate the centimeter, and then calculate by the addition and subtraction of the same denominator fraction. (23) Calculation Law of Fraction Multiplying Integer Fraction Multiplies Integer, Molecule is the product of Fraction Molecule Multiplying Integer, and denominator remains unchanged. (24) Calculation Law of Fractional Multiplication Fractional multiplication, the product of molecular multiplication is the numerator, and the product of denominator multiplication is the denominator. (25) Calculation rule of dividing a number by a fraction A number divided by a fraction is equal to the reciprocal of this number multiplied by the divisor. (26) Decimals are converted into percentages, and percentages are converted into percentages by moving the decimal point to the right by two places, followed by hundreds of semicolons; Convert percentages to decimals, remove the percent sign, and move the decimal point two places to the left. (27) Fractions are converted into percentages and percentage components. Fractions are usually converted into decimals (except three decimal places) first, and then decimals are converted into percentages; Convert percentages to decimals. First, rewrite the percentage into a fraction with the initials 100, and make a quotation that can be turned into the simplest fraction. Second, the primary school mathematics mouth determines the meaning classification 1, and what is the circumference of the graph? The sum of all the edges of a figure is the perimeter of the figure. 2. What is the area? The size of the surface of an object or the plane figure surrounded by it is called their area. 3. The relationship between the parts of addition: one addend = and-another addend 4. The relationship between the parts of subtraction: subtraction = minuend-difference minuend = subtraction+difference 5. The relationship between the parts of multiplication: one factor = product ÷ another factor 6. The relationship between the parts of division: Divider = Divider ÷ Quotient Divider = A graph composed of two rays drawn from a point is called an angle. (2) What is the vertex of an angle? The endpoint of an angle is called a vertex. (3) What is the edge of a corner? The rays that form an angle are called the edges of the angle. (4) What is a right angle? An angle of 90 degrees is a right angle. (5) What is a right angle? The two sides of an angle are on a straight line, and such an angle is called a right angle. (6) What is an acute angle? An angle less than 90 is an acute angle. (7) What is an obtuse angle? An angle greater than 90 and less than180 is an obtuse angle. (8) What is a fillet? The angle formed by a ray rotating around its endpoint is called a fillet, and the fillet is equal to 360.8, (1). What is perpendicular to each other? What is a vertical line? What is a drooping foot? When two lines intersect at right angles, they are perpendicular to each other, one of which is called the perpendicular of the other, and the intersection of these two lines is called the vertical foot. (2) What is the distance from a point to a straight line? Draw a vertical line from a point outside the line, and the distance between the point and the vertical foot is called the distance from the point to the line. 9. Triangle (1) What is a triangle? A figure surrounded by three line segments is called a triangle. (2) What sides does a triangle have? Each line segment forming a triangle is called an edge of the triangle. (3) What is the vertex of a triangle? The intersection of every two line segments is called the vertex of a triangle. (4) What is an acute triangle? A triangle with three acute angles is called an acute triangle. (5) What is a right triangle? A triangle with a right angle is called a right triangle. (6) What is an obtuse triangle? A triangle with an obtuse angle is called an obtuse triangle. (7) What is an isosceles triangle? A triangle with two equal sides is called an isosceles triangle. (8) What is the waist of an isosceles triangle? In an isosceles triangle, two equal sides are called the waist of the isosceles triangle. (9) What is the vertex of an isosceles triangle? The intersection of two waists is called the vertex of an isosceles triangle. (10) What is the base of an isosceles triangle? In an isosceles triangle, the side that is not equal to the other two sides is called the base of the isosceles triangle.
(1 1) What is the base angle of an isosceles triangle? The two equal angles on the base are called the base angles of an isosceles triangle. (12) What is an equilateral triangle? A triangle with three equilateral sides is called an equilateral triangle, also called a regular triangle. (13) What is the height of the triangle? What is the base of a triangle? Draw a vertical line from the vertex of a 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 of the vertex is called the bottom of the triangle. What is the sum of the internal angles of a triangle (14)? The sum of the internal angles of a triangle is 180. 10, quadrilateral (1) What is a quadrilateral? A figure surrounded by four line segments is called a quadrilateral. (2) What is equilateral? Two groups of parallelograms with parallel opposite sides are called parallelograms. (3) What is the height of the parallelogram? Draw a vertical line from one point on one side of the parallelogram to the other. The line segment between this point and the vertical foot is called the height of the quadrilateral. (4) What is a trapezoid? A quadrilateral with only one set of parallel sides is called a trapezoid. (5) What is the bottom of the trapezoid? A set of mutually equal sides in a trapezoid is called the bottom of the trapezoid (usually the shorter bottom is called the upper bottom and the longer bottom is called the lower bottom). (6) What is a trapezoidal waist? In a trapezoid, an unequal set of opposite sides is called the waist of the trapezoid. (7) What is the height of the trapezoid? Draw a vertical line from a point on the upper bottom to the lower bottom. The line segment between this point and the vertical foot is called the height of the trapezoid. (8) What is an isosceles trapezoid? An isosceles trapezoid is called an isosceles trapezoid. 1 1. What is a natural number? 0,1,2, 3, 4, 5, 6, 7, 8, 9,10 ... are all natural numbers (natural numbers are all integers). 12, what is rounding? When finding the divisor of a number, look at the number with the highest mantissa omitted. If it is 4 or less, the mantissa is discarded. If it is 5 or more, after removing the mantissa, add 1 to the previous number. This method of finding approximate value is called rounding. 13, the meaning and algorithm of addition (1) What is addition? The operation of combining two numbers into one number is called addition. (2) What is addend? The addition of two numbers is called addend. (3) What is harmony? The result of adding addends is called sum. (4) What is additive commutative law? When two numbers are added and the positions of addends are exchanged, their sum remains the same. This is called additive commutative law. What is subtraction? Given two numbers and one addend, the operation of finding the other addend is called subtraction. 15, what is the minuend? What is subtraction? What is the difference? In subtraction, the known sum is called the minuend, the subtracted known number is called subtraction, and the obtained unknown number is called the difference. 16, the relationship between the parts of addition: sum = addend+addend = and-another addend 17, and the relationship between the parts of subtraction: difference = minuend-subtree = minuend+difference 18, multiplication (/kloc- The simple operation of finding the sum of several identical addends is called multiplication. (2) What is a factor? Multiplying two numbers is called a factor. (3) What is a product? The number obtained by multiplying the factor is called the product. (4) What is the multiplicative commutative law? When two factors are multiplied, the positions of the factors are reversed and their products remain unchanged. This is called multiplicative commutative law. (5) What is the law of multiplicative association? When multiplying three numbers, multiply the first two numbers and then the third number, or multiply the last two numbers and then the first number, and the product remains unchanged. This is the so-called law of multiplication and association. 19, division (1) What is division? Given the product of two factors and one of them, the operation of finding the other factor is called division. (2) What is dividend? In division, the known product is called dividend. (3) What is a divisor? In division, a known factor is called divisor. (4) What is business? In division, the unknown factor is called quotient. 20. Relationship between parts of multiplication: product = factor × factor = product ÷ another factor 2 1, (kloc-0/) Relationship between parts of division: quotient = dividend ÷ divisor = dividend ÷ quotient (2) Relationship between parts of division with remainder: 23. What is a single number? A number with only one company name is called a single number. 24. What is a composite number? Numbers with two or more unit names are called composite numbers. 25. What is a decimal? Imitate the writing method of integers, write them on the right side of integer digits, separated by dots, and the numbers used to represent one tenth, one hundredth and one thousandth are called decimals.