Tisch
Learning goal of the first volume of Grade Three: 1. Knowing that the unit of length is millimeter, the concept of 1 millimeter is established, and the length of shorter objects is measured in millimeters and centimeters;
2. Thoroughly understand the calculation rules of pen addition within ten thousand, and the application rules can accurately calculate the addition problem of two-digit continuous carry;
3. Get to know quadrangles, understand their characteristics and classify quadrangles according to their characteristics;
4. Know the meaning of division by remainder and experience the actual background from remainder;
5. Know the time unit "seconds" and 1 minute =60 seconds; Can do some simple time calculation; Initially establish the time concept of hours, minutes and seconds, and develop the consciousness and habit of observing and cherishing time;
6. Master the oral calculation method of multiplying a number by an integer of ten, an integer of one hundred and an integer of one thousand, and perform the corresponding oral calculation; Know a simple algorithm of multiplying a number by integer ten, integer hundred and integer thousand;
7. Have a preliminary understanding of a score, can read and write a score, and can compare the molecular score of 1;
8. Understand the oral calculation of multiplying a number by an integer of ten.
Difficulties in learning the first volume of Grade Three:
1. Knowing the time unit hours, minutes and seconds, knowing that 1 minute =60 seconds, you can do some simple calculations about time;
2. Knowing the meaning of division with remainder comes from life;
3. Classify quadrangles according to their characteristics;
4. Which number adds up to ten, you should add 1 to the previous number, and remember to add1to the previous number when adding up;
Knowing that the unit of length is millimeter, you can measure the length of an object in millimeters.
extreme
Summary of knowledge points in the first volume of grade three: 1. Mm: mm is the unit of length and rainfall, abbreviated as mm in English.
1mm = 0.1cm = 0.01decimeter = 0.001m = 0.000001km.
2. centimeter: it is a unit of length measurement, equal to one hundredth of one meter. The unit of length, with the symbol of centimeter. ， 1cm = 1/ 100m。
1 cm = 10/0mm =0. 1 decimeter =0.0 1 m =0.0000 1 km.
3. decimeter: it is one of the metric units of length, and 1 decimeter is equivalent to one tenth of 1 meter.
0.000 1 km = 1 decimeter
0. 1 meter (m) = 1 decimeter
10cm = 1 decimeter
100 mm = 1 decimeter
4. Kilometers: Kilometers, also called kilometers, are units of length and are usually used to measure the distance between two places. It is the international standard unit of length measurement, and the symbol is km.
1 km (km) = 1 0,000m (m) =100,000m (cm) = 1 0,000mm (mm)
5. Ton: mass unit. In the metric system, one ton is equal to 1000 kg.
6. Addition: one of the four basic operations, which refers to the operation of combining two or more numbers and quantities into one number and quantity.
The addition symbol is the plus sign (+).
When adding, connect the items with a plus sign and put the sum after the equal sign (=). For example, if the sum of 1, 2 and 3 is 6, it will be written as: 1+2+3 = 6.
Name of addition part: "+"is a plus sign, the numbers before and after the plus sign are addends, "=" is an equal sign, and the numbers after the equal sign are sums.
For example: 100 (addend)+(plus sign) 300 (addend) = (equal to sign) 400 (sum)
Additive properties: (1) additive commutative law: a+b = b+a.
(2) Additive associative law: a+b+c=a+(b+c)
7. subtraction: one of the four operations, the operation of subtracting another number or quantity from one number or quantity is called subtraction.
Given the sum of two addends and one of them, the operation of finding the other addend is called subtraction.
The essence of subtraction: subtracting a number is equal to adding the reciprocal of this number.
8. Check calculation: After calculating the problem, use inverse operation (such as subtraction, addition, subtraction, multiplication and division, multiplication) to calculate it again, and check whether the results of the previous operations are correct.
Function of checking calculation: checking calculation can effectively detect errors in the calculation process, but it is not very effective in solving errors in thinking. By comparing the data obtained by checking calculation (using the results to derive conditions) with the original data, it is suggested whether the operation is correct.
9. Quadrilateral: A closed three-dimensional figure surrounded by four line segments that are not on the same line is called quadrilateral. It consists of convex quadrilateral and concave quadrilateral.
10. Parallelogram: Two groups of parallelograms with opposite sides are called parallelograms.
Tisso
Summary of knowledge points in the first volume of Grade Three: 1. Perimeter: the integral of the length of the edge surrounding a limited area is called perimeter, and the length of the graph is the perimeter of the graph. Therefore, the perimeter is equal to the sum of all the edges of the graph.
2. Estimate: According to the situation, make a general inference about the nature, quantity and change of things.
3. Remainder: In the division of integers, there are only two situations: divisible and non-divisible. When it is not divisible, a remainder is generated, and the remainder operation is: 1 It refers to the undivided part of the dividend in integer division.
For example, if 27 is divided by 6, the quotient is 4 and the remainder is 3.
Properties of remainder: The remainder has the following important properties (A, B and C are natural numbers):
(1) remainder is less than divisor;
(2) Dividend = Divider × quotient+remainder.
Divider = (dividend-remainder) ÷ quotient;
Quotient = (dividend-remainder) divider;
Remainder = dividend-divisor × quotient.
4. Seconds: Time unit Time unit second is the basic unit of time in the international system of units, and the symbol is S.
5. Minute: time unit, equal to 1/60 hours or 60 seconds.
6. multiplication: a shortcut to add the same numbers. The result of its operation is called product.
Names of numbers in the multiplication formula: "×" is the multiplication sign, numbers before and after the multiplication sign are called factors, "=" is the equal sign, and numbers after the equal sign are called products.
For example: 10 (factor) × (symbol) 200 (factor) = (symbol) 2000 (product)
7. Scores: Divide the unit "1" into several parts on average, and the number representing such one or several parts is called a score. The number representing this share is called the fractional unit.
The numerator is above the denominator, which can also be regarded as division. The numerator is divided by the denominator, and the opposite multiplication can also be expressed as a fraction.
8. Fraction line, numerator and denominator: The horizontal line in the middle of the score is called the fraction line, the number above the fraction line is called the numerator, and the number below the fraction line is called the denominator. Read it as a score.
Fractions can be expressed by division formula: for example, half equals 1 divided by 2, where 1 numerator equals dividend, fractional line equals divisor, denominator equals divisor, and 0.5 fraction equals quotient.
9. The origin of the score: The score has a long history in China, and the original form of the score is different from the present. Later, India appeared a score representative similar to China's. Later, the Arabs invented the fractional line, and the expression of the score became like this.
More than 200 years ago, the Swiss mathematician Euler said in his book "General Arithmetic" that it is impossible to divide a 7-meter-long rope into three equal parts because there is no suitable number to represent it. If we divide it into three equal parts, each part is 7/3 meters, just as 7/3 is a new number, we call it a fraction.
10. Possibility: Possibility refers to the probability of things happening, and it is a quantitative indicator contained in things and indicating the development trend of things.