How to teach mathematics in the second grade of primary school
Pay attention to the guidance of learning methods and let students innovate.
1. Practice. Kong Yu, a great educator, once said, "Knowing is not as good as being kind, and being kind is not as good as being happy." When teaching "derivation of trapezoid area formula", when students are eager to know the calculation method of trapezoid area and their thinking has been activated, the teacher does not explain mechanically, but guides students to cut out two trapezoid cardboard (two identical trapezoids are needed). When the students cut them out, the teacher asked: See which group can use the cardboard in their hands and turn them into the learned graphics. Students began to spell a pendulum (some groups spell a parallelogram with exactly the same trapezoid; Some people use two identical right-angled trapezoids to form a rectangle. When the students spoke their own spelling, the teacher asked, "What is the relationship between the bottom, height and area of the figure you spelled and the bottom, height and area of one trapezoid?" According to the relationship between them, can the formula for calculating the trapezoidal area be obtained? Through observation and with the help of the formed representation, each group of students quickly got the formula for calculating the trapezoidal area.
2. Guide questions and let students innovate. Asking questions and asking difficult questions is the beginning of exploring knowledge and finding problems. In teaching, teachers should start from the characteristics of students' strong curiosity and thirst for knowledge, guide students to think diligently and dare to ask questions, create a good atmosphere for students to ask questions, and give them methods to ask questions. Let students find problems, think about them from different angles, ask more questions, ask questions and express new opinions. Why can't the latter term of "ratio" be zero? Why don't you use "wait" instead of "wait" in the relationship between ratio, score and division? Why add and subtract fractions with different denominators first? As soon as the questions about general points are raised, students will find themselves interested and active in thinking, so they will speak more actively, and the relationship between ratio, score, integer and proportion will be clear. Students' initiative has been brought into play, and they are more eager to learn, good at learning and willing to learn.
Create a good atmosphere and let students dare to innovate.
Psychological research shows that only when students study in a relaxed, harmonious and autonomous environment can they be open-minded, quick-thinking and actively participate in learning activities, thus stimulating the generation of innovation. In order to cultivate innovative consciousness, we must establish the concept of taking learning and students as the teaching center, create an atmosphere and environment that respects students, change the relationship between teachers and students into the relationship of friends, move the platform among students, and change the teacher's teaching into the students' questions. Encourage students to express their opinions boldly, actively participate in teaching activities and dare to innovate.
Therefore, in the teaching process, we should make the classroom teaching lively and full of enthusiasm, form an unrestrained thinking space, and make students in a relaxed and happy psychological state. Teachers should respect every student, protect every student's innovative spirit, induce students to think independently, and encourage students to express their different views. Tap the potential fun in teaching materials and turn hard study into enjoyable study. Let all students have a successful experience. Practice has proved that group learning is an effective form of learning. In group learning, top students can give full play to their talents, middle students can get exercise, and students with learning difficulties can get help and improvement. Create a lively learning atmosphere for students, promote students to be proactive and explore hard, form psychological desire to explore and innovate, form personality characteristics with innovative spirit to acquire and use knowledge, and promote the formation of innovative personality qualities that students can creatively adapt to environmental changes.
Complete set of mathematical formulas for grade two
1 and the two meanings of multiplication;
(1), say: What is the sum of several?
2, say: What is the sum of several?
2. Three meanings of division:
(1) means: divide a number into several parts on average, and each part is several parts. (the meaning of sharing equally)
(2) indicates that there are several numbers in a number. (including the meaning of division)
(3) indicates that one number is several times that of another. (the meaning of multiple division)
Find out how many times one number is another number, and then divide it.
4. Know that one number is several times that of another number, and find a number by multiplication.
5. Know that one number is several times that of another number, and find another number by division.
6. Find the multiple of a number by multiplication.
7. Average formula: total? Number of copies = number of copies
8. The formula includes division: total? Number of copies = number of copies
9. Be familiar with the names of all parts of multiplication and division and the reading of formulas.
3? 4= 12
Multiplier product
12? 4=3
Divider quotient
Read: 3 times 4 equals 12. Reading: 12 divided by 4 equals 3.
10, on the map, it is generally up north, down south, left west, right east.
1 1. If facing east, the back is west, the left is north, and the right is south. If facing west, the back is east, the left is south and the right is north. If you face south, your back is north, your left is east and your right is west.
12, 1 =60 minutes, 1 minute =60 seconds.
13, elapsed time = end time-start time = end time-elapsed time end time = start time+elapsed time.
14, the common time unit is sometimes, minutes and seconds.
15. There are 12 big squares and 60 small squares on the clock. It takes 1 hour to walk a big square in an hour hand, 1 minute to walk a Little Square in a minute hand and 5 minutes to walk a big square in a minute hand.
16. In the division formula with remainder, the remainder must be less than the divisor.
17. According to the relationship between the parts of division, the following formula can be derived:
Dividend = divisor? Quotient+remainder divisor = (dividend? Remainder)? Quotient = (Dividend? Remainder)? Divider remainder = dividend? The dividing line? business
18, in the formula without brackets, there are addition and subtraction and multiplication and division. Calculate multiplication and division first, then add and subtract. If there is only addition and subtraction or only multiplication and division, it should be calculated from left to right. Formulas in brackets should be calculated first.
19. We usually refer to all directions as "East, West, South, North, Southeast, Northeast, Southwest and Northwest".
20, 10 One thousand is ten thousand; 10 One hundred is one thousand; 10 Ten is one hundred.
2 1. From the right, the first place is the unit, the second place is ten, the third place is one hundred, the fourth place is one thousand, and the fifth place is ten thousand.
22. Pay attention when reading: No matter how many zeros there are at the end, there are one or more zeros in the middle, and read only one zero. Note when writing numbers: there is nothing on any number, just fill in a zero placeholder on that number.
23, compare the size of the quantity should be paid attention to:
1, the number with more digits is greater than the number with less digits;
2. When the number of digits is the same, the number with the highest digit is greater than the number with the highest digit; When the highest digit is the same, the ratio of one digit to another digit in descending order, which digit is larger, indicates that the number is larger.
24. When reading, read from the (highest) position in order (from high to low).
25. Length units: kilometers, meters, decimeters, centimeters and millimeters.
Expressed in letters: km, m, dm, cm, mm.
26. The advance rate between commonly used "adjacent" length units is "10", the advance rate between "separated" 1 00 "and the advance rate between two" separated "length units is" 1000 ". We also derived seven unit conversion formulas, namely:
1m = 10 decimeter 1m= 10dm 1 decimeter =10 cm1DM =10 cm.
1cm = 10mm 1cm = 10mm 1m = 100cm 1m = 100cm。
1 decimeter =100 mm1DM =100 mm1m =1000 mm/m =1000 mm.
1 km = 1 000m1km =1000m
27. We also know that there are (10) cells in 1cm, and the length of each cell is1mm. 1 decimeter is about the length of a palm. 1 cent coins are about 1 mm thick. When long distance is expressed, it is expressed in "kilometers".
28. Written calculation method of three-digit addition (carry addition): (1) The same digits are aligned; (2) Starting from the unit; (3) Whoever reaches 10 will be promoted to 1.
29. Written calculation method of three-digit subtraction (abdication subtraction): (1) Same digit alignment; (2) from the unit; (3) If the reduction is not enough, borrow a 1, and then add this 10 to reduce it.
When estimating in this unit, the number can be regarded as an integer or an integer, so that the estimated answer will be closer to the actual answer.