1. Summary of last semester's knowledge points of mathematics in grade two of primary school
Addition and subtraction and mixed addition and subtraction 1, addition and subtraction
The writing order of addition and subtraction is the same as that of oral calculation, which is calculated from left to right in turn.
(1) The addition calculation can be done step by step or vertically. The calculation method is the same as adding two numbers. All the same numbers should be aligned, starting with single digits.
② The continuous subtraction operation can be calculated step by step or written as vertical calculation. The calculation method is the same as subtracting two numbers. The same numbers should be aligned, starting with single digits.
2. Add, subtract and mix
The operation order of mixed addition and subtraction formula is the same as vertical writing and addition and subtraction.
3. When writing vertically, you can calculate the mixed operation of addition and subtraction step by step. The method is the same as adding (subtracting) two numbers. The same number of digits should be aligned and counted from single digits. You can also write in a simple way, in a vertical row. First, complete the calculation of the first step, and then add (subtract) the second number with the result of the first step.
2. The second grade of primary school mathematics knowledge points in the last semester are summarized.
The unit of length 1, the necessity of unifying the unit of length and the function of the unit of length.
2. Know cm: Know the length of cm, and how long it is greater than 1 cm, expressed by the letter CM; Small objects, in centimeters; Measure the length of an object in centimeters with a ruler.
3, know the meter: know the length of the meter, how long it is greater than 1 meter, represented by the letter m, and large objects are usually measured in meters; Measure the length of an object in meters with a ruler; The relationship between centimeter and meter: 1 meter = 100 centimeter.
4. Know the line segment: The characteristics of the line segment: it is straight and its length can be measured; Will use a ruler to measure the length of line segments (only whole centimeters and meters); According to the number of lines in the graph; Draw a line segment: Draw a line segment according to a given length (only the whole centimeter).
5, problem solving: estimate the length of the object, choose the appropriate length unit (limited to centimeters and meters).
3. Mathematics knowledge points of the second grade of primary school in the last semester.
1, the perimeter of a rectangle = (length+width) ×2C=(a+b)×2 2, and the perimeter of a square = side length× 4c = 4a.
3. Area of rectangle = length× width S=ab
4. Area of a square = side length × side length S = a ... a = a.
5. Area of triangle = base × height ÷2S=ah÷2.
6. parallelogram area = bottom x height S=ah
7. trapezoidal area = (upper bottom+lower bottom) × height ÷2S=(a+b)h÷2.
8. Diameter = Radius× 2D = 2r Radius = Diameter ÷2r=d÷2
9. The circumference of a circle = π× diameter = π× radius× 2c = π d = 2π r.
10, circular area = pi × radius× radius? =πr
1 1, the surface area of a cuboid = (length× width+length× height+width× height) × 2.
12, cuboid volume = length× width× height V=abh.
13, the surface area of the cube = side length × side length× 6s = 6a.
14, volume of cube = side length × side length × side length v = a.a.a = a.
15, lateral area of cylinder = circumference of bottom circle × height S=ch.
16, surface area of cylinder = upper and lower bottom area+side area.
s = 2πr+2πRH = 2π(d÷2)+2π(d÷2)h = 2π(c÷2÷π)+Ch
17, cylinder volume = bottom area × height V=Sh
V=πrh=π(d÷2)h=π(C÷2÷π)h
4. Summary of last semester's knowledge points of second grade mathematics in primary school
Calculation formula quantity relation:
1, number of copies × number of copies = total number of copies, total number of copies/number of copies = number of copies, total number of copies/number of copies = number of copies.
2, 1 multiple × multiple = multiple, multiple1multiple = multiple, multiple = 1 multiple.
3, speed x time = distance, distance/speed = time, distance/time = speed.
4. Unit price × quantity = total price, total price/unit price = quantity, total price/quantity = unit price.
5. Work efficiency × working hours = total workload, total workload ÷ work efficiency = working hours, total workload ÷ working hours = work efficiency.
6. Appendix+Appendix = sum, and-one addend = another addend.
7. Minus-Minus = difference, Minus-Minus = Minus, Minus+Minus = Minus
8. Factor × factor = product, product ÷ one factor = another factor.
9. Dividend/divisor = quotient, dividend/quotient = divisor quotient × divisor = dividend
Formula of sum and difference problem
(sum+difference) ÷2= large number
(sum and difference) ÷2= decimal
And folding problems.
Sum \ (multiple-1)= decimal
Decimal × multiple = large number
(or sum-decimal = large number)
Difference problem
Difference ÷ (multiple-1)= decimal
Decimal × multiple = large number
(or decimal+difference = large number)
5. Summary of last semester's knowledge points of second grade mathematics in primary school
First, a preliminary understanding of multiplication: 1, which means that several additions are calculated by multiplication. The same addend × the number of the same addend.
2. Name: Multiplier× Multiplier = Product
Second, the multiplication formula of 1-9: memorize the formula and know the multiplication formula orally.
1, supplementary formula.
2. Write the multiplication formula according to the formula and the multiplication formula according to the picture.
Third, solve the problem.
1, knowing the number and number of each, what is a * * *? Each quantity × number = a * * * number.
2. Comparison of addition and multiplication: What is a * * *?
Understand the meaning of the question, carefully examine the question, and choose the method: look at the unit, divide, add the same unit, and multiply different units.
3. The algorithms of multiplication, addition and subtraction are diversified: different solutions are selected according to different observation directions. Multiplication first, then addition and subtraction.