Percent: A number indicating that one number is a percentage of another number is called a percentage, and a percentage is also called a percentage or percentage. Discount, interest rate, germination rate, etc. (7) Reciprocity of fractions, decimals and percentages (8) Positive number, zero number and negative number (9) Odd number, even number (10) prime number and composite number: prime number and factorization prime factor. The minimum prime number 2 and the minimum composite number 4, 1, are neither prime numbers nor composite numbers.
Divider, multiple: greatest common divisor, least common multiple (12) reciprocal: zero has no reciprocal (13) divisible: the number divisible by 2 ends in an even number; Numbers divisible by 5 end with numbers divisible by 0 or 5 or by 3 or 9; The sum of single digits can be divided by 3 or 9 by 4 or 25; The last two digits can be divisible by 4 or 25. 125 divisible: the last three digits are divisible by 8, 125 and11; The difference between the sum of numbers on odd digits and the sum of numbers on even digits can be divided by 1 1 and then divided by 7, 1 1, 65438.
14), reading and writing large numbers: unit, million, billion (13), unit conversion: length unit: mm, cm, decimeter, meter, kilometer. Area units: square centimeter, square decimeter, square meter and square kilometer. 1 ha = 10000 m2, 1000 m2 =1000 ha.
Unit of volume: 1 m3 = 1000 cubic decimeter 1 cubic decimeter = 1 liter 1 cubic centimeter = 1 ml? Weight unit:1t =1000kg1kg =1000g Time unit: day, hour, minute and second.
Four operations of 1, addition, subtraction, multiplication and division:? Additive commutative law, the law of multiplicative association? 2. Simple operation: (splitting, summation of series)? 3. Square? Step 4 estimate
The concept of ratio: the division of two numbers is also called the ratio of two numbers. 2. Ratio: The quotient obtained by dividing the former term of the ratio by the latter term is called the ratio. 3. The basic nature of the ratio: 4. Concept of proportion: Two expressions with equal proportion are called proportion (proportional expression).
Proportional quantity: positive proportion: two related quantities, one changes and the other changes, and the ratio of corresponding values is fixed (not zero). That is: y\x=k, these two quantities are called proportional quantities, and the relationship between the two quantities is called proportional relationship. (y=kx)
Inverse relationship: xy=k? 7. Scale = distance on the map: actual distance? 8. Solution ratio: Find the unknown term in the ratio, which is called solution ratio? 9. The basic nature of proportion: Is the inner product equal to the outer product? Being able to properly use proportion to solve application problems is the highest level of problem-solving that should be used from the beginning of junior high school.
The Concept of Equation: An Equation with Unknown Numbers? 2. Solve the equation? 3, column equation to solve application problems? Essence: looking for an equal relationship? Frequently asked questions: itinerary, items, concentration, interest rate? Application problems in discounted life, etc.
Angle: acute angle, right angle and obtuse angle? What is the sum of the internal angles of a triangle? 2. Perimeter: The sum of two sides of the triangle is greater than the third side. ? Square, rectangle, isosceles trapezoid, Circular and special sectors
Area: triangle, square, rectangle, trapezoid, circle and special sector. The equal product transformation of triangle area is the key point. Irregular graphic area, graphic transformation, methods: translation, rotation, cutting, complement. 4. Surface area of space figure: cube, cuboid, cylinder and geometric combination.
Volume: cylinder (cube, cuboid, cylinder) cone. Equal product transformation: main problem: volume calculation of shape transformation combination.
Basic statistical charts: bar chart (column chart), fan chart (pie chart), line chart, drawing, analysis and application II. Count: (simple arrangement and combination) 3. Equal possibility: (simple probability statistics)
Common sense of life: in leap years, the last number can be divisible by 4. For example, the last number is 00, which can be divisible by 400. In normal years, there are 28 days in February, 365 days in leap years and 366 days in a year. 2. Optimization: simple optimization and overall planning? 3. Reasoning: the principle of inclusion and exclusion, the simple venn diagram of intersection, union and complement of sets.