123+28=
89 1+ 12=
19+2 1=
28+9=
6+5= 55-50= 26-6= 8+3= 24-4= 7+70= 2+80=
12-7= 30+2= 50+50= 20+30=
98-40= 66-6= 80-30= 60+ 10=
70+30 -40= 43-3+20= 100-50- 10= 40+2=
18-9= 3+42= 19-6= 7+27=
38-8= 12+6= 45+60= 90-20=
48-8= 82+3= 8+30= 4+24=
30+8= 50-20= 15-9-3= 9+7-8=
14-7+8= 10-5+5= 2+5+9= 70-20+9=
90+7-60= 10+2-3= 88-8-80= 13-9=
16-9= 15-9= 17-9= 12-9=
18-9= 1 1-9= 14-9= 17-9=
16-9= 19-9= 9+6= 8+9=
14-9+7= 15-9-5= 6+7-9= 13-9+8=
17-9= 5+9= 9+8= 3+9=
9+6= 14-9= 17-9= 7+5=
8+4= 8+8= 12-7= 12-8=
16-8= 14-7= 17-8= 13-7=
12-8= 16-7= 15-8= 17-7=
1 1-7= 13-8= 18-8= 1 1-8=
12-7= 13-7= 12-8= 1 1-9=
4+2= 8-3= 3+6= 9-4=
40+20= 80-30= 30+60= 90-40=
10+3= 7+30= 5+70= 2+ 10=
30+7= 70+5= 12-2= 37-7=
75-5= 12- 10= 37-30= 75-70=
70+4= 46-6= 33-30= 17-7=
58-50= 9+60= 20+5= 50+ 1=
30+5= 30+6= 70+3= 2 1+70=
46+20= 30+ 14= 2 1+7= 46+2=
3+ 14= 4 1+7= 30+28= 46+2=
46+20= 3+55= 53+5= 46+3=
6+62= 19+70= 4+32= 50+49=
63+6= 30+28= 40+ 12= 45+4=
33+40= 56+30= 3+34= 38+20=
20+38= 3+56= 20+78= 25+30=
25+30= 25+3= 3 1+23= 54-30=
68-40= 93-20= 39-20= 77-40=
67-30= 68-20= 48-3= 59-30=
69-40= 75-3= 75+3= 26-4=
85-70= 46-6= 73-50= 87-4=
99-7= 56-3= 72-20= 27-7=
95-70= 44-30= 58-40= 48-3=
48-30= 57-6= 47-6= 59-30=
69-40= 75-3= 75+4= 56-30=
34-3= 87-6= 74-2= 78-60=
34-30= 78-6= 74+2= 75-3=
88-5= 56-4= 89-7= 46-20=
69-40= 47-3= 38-7= 84-4=
63-60= 49-4= 94-70= 39-3=
7 1-30= 57-30= 49-5= 97-60=
47-3= 78-20= 47-5= 48-5=
32-30= 65-4= 53-50= 68-5=
47-4= 74-20= 86-5= 74-3=
75-30= 68-50= 47-30= 75-40=
86-50= 74-30= 74-50= 57-30=
28-6= 47-3= 98-20= 89-60=
39-8= 43-30= 38-20= 12+45=
36+23= 87+35= 65+24= 42+40=
78+35= 64+32= 32+53= 67-42=
68-5= 4+23= 35+42= 43+54=
67-37= 78-46= 45+32= 76-56=
74-30= 35-32= 38-7= 26+63=
69-7= 5+74= 63-4 1= 54-42=
38- 1 1= 75+4= 46+30= 20+69=
75-4= 46-30= 69-20= 32+37=
4+65= 57-35= 88-63= 58+20=
78-5= 87-40= 76-3= 76-30=
4+35= 35+4= 42+40= 3+56=
24+8= 36+5= 6+4= 5+8=
9+7= 26+4= 5+38= 9+ 17=
46+4= 5+48= 9+37= 8+35=
14+6= 35+3= 2+46= 24+4=
35+5= 4+46= 26+3= 35+7=
6+46= 28+4= 36+5= 47+2=
7+52= 36+50= 47+7= 7+25=
37+8= 63+6= 4+58= 28+20=
42+9= 7+76= 89+2= 8+ 15=
46+30= 28+5= 34+6= 56+40=
3+29= 35+3= 2+46= 24+4=
5+26+32= 180-69= 86-52+9= 78-6+ 1= 60-50+20=
70+30 -40= 43-3+20= 100-50- 10= 40+2= 50-23=
20+65-20= 80- 10+20= 10+2-3= 88-8-80= 10+ 10+30=
14-7+8= 10-5+5= 2+5+9= 70-20+9=
90+7-60= 10+2-3= 88-8-80= 13-9=
2. Vertical calculation (40 points)
8 9 7 6 4 6
+ 5 + 8 +5 + 19 +25 +56
- ______ - - - -
7 96 98 32 45 70
+34 +4 - 19 -28 -29 -35
- - - - - -
8 1 62 45 77 45 27
-80 -34 -5 -69 -37 - 17
- - - - - -
8 6
_ ( )( )
__________
2 6
20( )
- 16
_______
four
First, how to grasp the teaching requirements of "lovely campus"?
This is the first preparatory class for newly enrolled children to know the numbers below 10. The purpose is to understand students' ability to observe scene diagrams and count through their counting activities, and to make some preparations for students to learn mathematical symbols below 10 in the future. Therefore, the teaching requirements of this class are mainly to explain clearly what animals are on the map, talk about the number of animals by counting, and guide students to observe and count in an orderly manner.
When organizing teaching activities, teachers are advised to bring students to the campus first, so that students can say what "numbers" they have found while watching, such as: "Our school has 3 trees and 4 floors". In the second half of the class, go back to the classroom and show the scene map. Let the students see what "numbers" are in the animal school. What's the difference with the number in our school? When observing the scene map, students should explain clearly what is in the map because of the large amount of information. It also needs a step-by-step guidance process. Teachers are advised to provide students with ample opportunities to say what is in the picture. Such as "there is an elephant in the picture" and "there is a bear in the picture", which is the basis for students to count.
Students should be guided to describe information with numbers in the process of speaking. On the basis of students exchanging campus information and pictures, teachers can guide students to describe the information in pictures with numbers. For example, "There are trees on campus, so how many trees are there?" "There are bears in the picture, so how many bears are there?" In this way, students need to count the small animals in the picture to answer the above questions. In the process of student counting, some students may miss the count, or most students miss the count. This phenomenon is normal for students. Students can count again in class to correct the mistakes in counting.
In the process of speaking, we should also guide the observation method, because the information presentation is generally irregular, students need to observe up and down, left and right when counting, and teachers should guide them when counting.
In the consolidation exercise, some teachers adopt the teaching method of "finding numbers from students", which will help students know numbers. Because the newly enrolled students have certain life experience in counting, by counting the numbers on their bodies, the newly enrolled children have a sense of intimacy with mathematics.
In this class, through the above activities, teachers can understand students' existing mathematical cognitive foundation, thus laying a good starting point for subsequent learning. Therefore, this class mainly focuses on language communication between teachers and students, and generally there are no abstract digital symbols.
Secondly, when teaching "within 10" and "within 20", most students already know these numbers and can count them in kind. How to grasp the key points of classroom activities in teaching?
Now most first-year students have received preschool education and family education, so it is normal for them to know that the number within 10 and the number within 20, which also creates a good foundation for setting the starting point of classroom teaching. However, related research shows that there is still a great disharmony between many students' understanding of the symbols of numbers and their understanding of the meanings of symbols, and the foundations among students are also very different. Some students can count and read directly, but they can't clearly explain the meaning of numbers. Therefore, in teaching activities, teachers should pay attention to the understanding of the meaning of numbers, especially the understanding of numbers within 20, and should pay attention to the initial establishment of decimal numerical system.
If you know the numbers within 20, you can directly show some dozens of numbers for students to read directly. Then ask the students to put these numbers together with their learning tools. Through the process of placing, let the students know that more than a dozen numbers are composed of "a ten and several ones". With the images of these numbers in students' minds, they will be remembered when they see the numbers in the future, which is very helpful for students to establish their position and values.
Third, compare the weight of objects. Why don't you tell students the method of weighing directly, but go through the process of "seeing", "weighing" and "weighing"
The teaching purpose of this part is to help students establish an intuitive feeling of quality through various activities and experiences. Students need rich direct experience to support the comparison of object weights. Simple "weighing" can only tell students an abstract result, but it can't intuitively make students feel who is more important than who is lighter. Therefore, activities such as "talking" and "weighing" are important methods to help students establish an intuitive feeling of the weight of objects and judge the relationship between the weights of objects. There are several considerations for arranging these contents in the textbook: First, let students perceive the quality of objects in activities and establish the experience of weight between objects. Second, through a series of activities, let students know that there are various ways to compare the weight of objects; The third is to infiltrate the idea of flexibly using different comparison methods according to the actual situation of the comparison object;
For example, in the content of "Tell me about it", because students have some experience in judging the weight of two objects, they can use their original experience to directly judge who is lighter and heavier. In this activity, we should not only make full use of students' original experience to judge, but also guide students to describe the weight of two objects in standardized language. For example, according to the picture on the seesaw, the language of students' narration is often "bear heavy" or "monkey light", which is not standardized enough to judge. At this time, the teacher should guide the students to say "bears are heavier than monkeys" or "monkeys are lighter than bears". In the activity of "point by point", it is mainly to let students know that when the relationship between two or more objects is not obvious and cannot be judged by reference, they need to choose the method of "point by point". At the same time, it plays a very important role in the process of students' weighing, that is, it helps students to gradually establish the experience of weight between objects, which will have an important impact on students' judgment of weight between objects in the future. The method of "weighing" is that two objects cannot be judged by "weighing". At this time, "weighing" has become a necessary method.
Therefore, the three groups of problem scenarios arranged in the textbook have their own emphasis. In these activities, students can not only feel different ways to judge the weight of objects, but also deepen their real understanding of the meaning of weight between objects.