Tisch
Length unit 1 cm = 10/0mm
1 decimeter = 1 0cm1decimeter =100mm.
1 m = 10 decimeter 1 m = 100 cm 1 m = 1000 mm
1km =1000m1km =10000 decimeter1km =100000 cm1km =100000.
mass unit
1t = 1000kg 1kg = 1000g 1kg = 1kg。
Subtraction: 1, minuend-subtraction = difference 2, subtraction = minuend-difference 3, minuend = difference+subtraction.
Addition: 1, Addendum+Addendum = and 2, Addendum = and-Addendum.
Addition and subtraction within 10 thousand
Appendix+Appendix = sum-1 addend = another 1 addend.
Minus-Minus = Difference Minus-Difference = Minus+Minus = Minus
Three-digit addition and subtraction: the parity pairs are neat, counting from single digits.
extreme
The check calculation of addition is 1, the position of the exchange addend, and the sum is unchanged.
2. Subtracting one addend from the sum equals another addend.
Check calculation of subtraction
1, plus or minus the difference equals the minuend.
Characteristics of quadrilateral
1, four straight edges 2, four corners 3, closed graph
Parallelogram feature
1, the opposite side is equal to 2, and the diagonal is equal to 3, which is easy to deform.
Definition of perimeter: the length of a closed figure in one week.
The circumference of a rectangle = length+width+length+width = (length+width) ×2
Circumference of a square = side length ×4
Side length formula: length of rectangle = perimeter ÷2- width of wide rectangle = perimeter ÷2- length.
Division with remainder: The remainder is always less than the divisor.
Have a remainder:
Dividend = divisor × quotient+remainder quotient = (divisor-remainder) ÷ Divider = (divisor-remainder) ÷ quotient
Uncomplete: dividend = divisor × quotient = dividend ÷ divisor = dividend ÷ quotient.
Tisso
Minutes and seconds: 1 century = 100 1 year = 65438+February 1 day =24 hours 1 hour =60 minutes 1 minute =60 seconds/kloc-.
The big month (3 1 day) includes: 1, 3, 5, 7, 8,10,65438+February.
Abortion (30 days) includes April, June and September, 165438+ 10.
February 28th in a normal year and February 29th in a leap year; There are 365 days in a normal year and 366 days in a leap year, with a leap year every four years.
Multiply 0 by any number to get 0 factor × factor = product ÷ 1 factor = another 1 factor.
Score:
Significance of fraction: divide an object into several parts on average, among which several parts.
Meaning of denominator: divide an object into several parts on average.
The meaning of molecules: some of them
Score comparison size:
The numerator is the same, the smaller the denominator, the greater the score;
The denominator is the same, and the larger the numerator, the greater the score.
Simple calculation of fractions: denominator unchanged, numerator addition and subtraction.