1 x number of shares per share = total number of shares ÷ number of shares = 2 1 multiple × multiple ÷ 1 multiple = multiple ÷ multiple = 1 multiple 3 speed × time = distance \ Total price ÷ quantity = unit price 5 Work efficiency × working hours = total workload ÷ Work efficiency = total working hours ÷ Working hours = work efficiency 6 Addendum+Addendum = sum-one Addendum = another Addendum 7 Minus-Minus = Difference Minus-Difference = Minus+Minus = minus 8 factor × factor = quotient divided by number ÷. Square c perimeter s area a side length perimeter = side length× 4c = 4a area = side length× side length S=a×a 2 cubic v: volume a: side length surface area = side length× side length× 6s table = A× A. A×a 3 rectangle c perimeter s area a side length perimeter = (length+width )× 2c = 2 (a+b) Kloc-0/) Surface area (length× width+length× height+width× volume = length× width× height V=abh 5 triangle S area A bottom H height area = bottom× height ÷2 s=ah÷2 triangle height = area× 2 bottom triangle bottom = area× 2 ÷. × height ÷2 s=(a+b)× h÷2 8 circular S area c perimeter ∏ d= diameter r= radius (1) perimeter = diameter× ∏ = 2×××× radius c =∏ d = 2. Bottom area r: bottom radius c: bottom perimeter (1) lateral area = bottom perimeter x height (2) surface area = lateral area+bottom area x 2 (3) volume = bottom area x height (4) volume = lateral area ÷ 2 x radius 10 cone v: volume h: height. Base area r: base radius volume = base area × height ÷3 Total number ÷ Total number = formula (sum+difference) ÷ 2 = large number (sum-difference) ÷ 2 = sum of decimal and multiple problems ÷ (multiple-1) = decimal × multiple. = Decimal Decimal × Multiply = Large number (or Decimal+Difference = Large number) Tree planting problem 1 Tree planting problem on the non-closed line can be mainly divided into the following three situations: (1) If trees are planted at both ends of the non-closed line, Then: number of plants = number of segments+1 = total length ÷ plant spacing-1 total length = plant spacing × (number of plants-1) plant spacing = total length ÷ (number of plants = number of nodes = total length ÷ plant spacing = Then: number of plants = number of nodes-1 = total length ÷ spacing between plants-1 total length = spacing between plants × (number of plants+1) spacing between plants = total length ÷ (number of plants +0÷ difference between two distributions = number of shares participating in distribution (. Meeting distance = speed × meeting time = meeting distance; The sum of speed and speed = meeting distance; Meeting time; Catch up with the problem; Distance = catch up with time; Distance; Speed difference = catching distance; Catch up with time; Downstream velocity =-water velocity = (downstream velocity+countercurrent velocity) ÷2 Water velocity = (downstream velocity-countercurrent velocity) ÷2 Concentration problem Solute weight+solvent weight = solution weight ÷ solution weight × 100% = concentrated solution weight × concentration = solute weight ÷ concentration = solution. × 100% increase or decrease = principal× increase or decrease percentage discount = actual selling price ÷ original selling price× 1 00% (discount <1) interest = principal× interest rate× time after tax interest = principal× interest rate× time × (1-) One number MINUS the sum of two numbers; One number MINUS the difference between two numbers; The quotient of one number multiplied by two numbers; A number divided by the product of two numbers; The quotient of one number divided by two numbers; The sum of several numbers divided by a number, etc. This part is only used for simple operation. Algorithms include: four algorithms for integers, four algorithms for decimals and four algorithms for fractions. It is required to master the algorithm on the basis of understanding and be skilled in using it to calculate. The application of formulas in primary school mathematics focuses on two aspects: 1. The algorithm or property is expressed by an alphabetic formula: additive commutative law: A+B = B+A additive associative law: (A+B)+C = A+(B+C) multiplicative commutative law: ab=ba multiplicative associative law: (ab)c=a(bc) multiplicative distributive law: A (A). Volume calculation formula Rectangular circumference: c = 2 (a+b) Square circumference: c = 4a circumference: c = 2π r, or (πd) Rectangular area: S=ab Square area: S = A2 parallelogram area: S=ah Circular area: S=πr2 Cuboid volume: V = ABC surface area s = 2 (AB+AC+) Teachers should carefully study the syllabus, carefully study the teaching materials, correctly understand the depth and breadth of the basic knowledge required by the syllabus, and pay attention to cultivating students' ability while making them understand and master the knowledge. When their ability develops, it will promote their understanding and mastery of knowledge. They complement each other and are inseparable. Travel can usually be divided into the following categories: encounter problems: speed and × encounter time = encounter distance; Catch-up problem: speed difference × catch-up time = distance difference; Running water problem: the key is to grasp the speed of water without affecting the time of catching up and meeting; Downstream speed = boat speed+water speed = boat speed-water speed = (boat speed+water speed) ÷2 Water speed = (boat speed-water speed) ÷2 (that is, as long as there are two of the four quantities of boat speed, water speed, boat speed and water speed, the other two can be found) Circle stroke: grab. Complex trips: including multiple encounters, trains crossing bridges, two-dimensional trips, etc. Define the theorem formula triangle area = base × height ÷2. Formula S= a×h÷2 square area = side length× side length formula S= a×a rectangular area = length× width formula S= a×b parallelogram area = bottom× height formula S= a×h trapezoid area = (upper bottom+lower bottom) × height ÷2 formula s = (a+b) cuboid volume. Volume = bottom area × height formula: V = volume of AAA cube = side length × side length × side length formula: V = perimeter of V = aaa circle = diameter × π formula: L = π d = area of 2π r circle = radius× radius× π. Formula: S = CH = π DH = 2π RH Surface area of a cylinder: The surface area of a 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 = V = volume of SH cone = 1/3 bottom × product height. Formula: V= 1/3Sh Fraction addition and subtraction: use denominator to add and subtract fractions, only add and subtract numerators, and the denominator remains unchanged. Fractions of different denominators are added and subtracted, first divided, then added and subtracted. 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. Unit conversion (1)1km =1km =1000m1m =1decimeter1decimeter =1cm/km. 38+0 square decimeter = 100 square centimeter 1 square centimeter = 100 square millimeter (3) 1 cubic meter = 1000 cubic decimeter 1 cubic decimeter = +0000kg 1kg = 1000g = 1kg = 1kg(5) 1 ha = 10000 m2 1 mu = 666.666 m2(6)654366 m2。 1 cubic centimeter quantity relation 1. Unit price × quantity = total price 2. Single output × quantity = total output 3. Speed × time = distance 4. Work efficiency × time = total workload. ...