= work efficiency 6, single output × quantity = total output ÷ quantity = total output ÷ single output = quantity 7, income × tax rate = tax payable. Interest/principal × 100%= interest rate. Interest = principal x interest rate x time. Interest tax = interest
Interest x 5%. After-tax interest = principal × interest rate× time × (1-5%). 8. Appendix+addend = sum, and-one addend = another addend.
9. Minus-Minus = Minus-Minus = Minus+Minus = Minus 10, factor × factor = product, one factor = another factor.
1 1, dividend/divisor = quotient dividend/quotient = divisor quotient × divisor = dividend
Total number ÷ total number of copies = average 12, concentration problem.
Solute weight+solvent weight = solution weight. The weight of solute/solution × 100% = concentration. Solution weight × concentration = solute weight. Solute weight/concentration = solution weight 13, profit problem.
Profit = selling price-cost. Profit rate = profit/cost × 100%
14, fractional percentage problem: the key is to find the standard quantity, which is unit one. If the unit "1" is known, it is calculated by multiplication; Ruo unit
An unknown number, calculated by division.
1) Simple fraction and percentage application problem: unit "1"× fraction rate = comparative quantity ÷ fraction rate = unit"1"2) How much is A more (or less) than B? (A-B)
Calculation formula of mathematical graphics in primary schools
1, square (c: perimeter s: area a: side length)
Circumference = side length ×4 C=4a area = side length× side length S=a×a 2, cubic (v: volume a: side length)
Surface area = side length × side length× ×6 S table =a×a×6 volume = side length× side length× side length v = a× a× a.
3. rectangle (c: perimeter s: area a: side length)
Circumference = (length+width) ×2 C=2(a+b) area = length× width S=ab 4, cuboid (v: volume s: area a: length b: width h: height)
(1) surface area = (length× width+length× height+width× height )× 2s = 2 (ab+ah+BH) (2) volume = length× width× height V=abh.
5. Triangle (S: area A: base H: height)
Area = bottom × height ÷2 s=ah÷2
Triangle height = area ×2÷ triangle base = area ×2÷ height 6. Parallelogram (s: area a: base h: height)
Area = bottom × height s=ah
7. trapezoid (s: area a: upper bottom b: lower bottom h: height)
Area = (upper bottom+lower bottom) × height ÷2 s=(a+b)× h÷2.
8. circle (s: area c: circumference d= diameter r= radius pi:? )
(1) perimeter = diameter× л = 2×л× radius C=лd=2лr
(2) area = radius × radius× ×л S=л
8. circle (s: area c: perimeter d= diameter r= radius perimeter ratio:? )
(1) perimeter = diameter× л = 2×л× radius C=лd=2лr
(2) area = radius× radius× л s = л R2
9. Cylinder (V: volume H: height S: bottom area R: bottom radius C: bottom circumference)
(1) lateral area = bottom perimeter × height =ch(2лrh or лdh) (2) surface area = lateral area+bottom area ×2.
S=ch+(c÷л÷2)2×2，S=2лrh+лr2×2
S=лdh + л)(2d2？ ×2 (3) volume = bottom area× height V=sh(лr2h or л)(2d2? h)