Calculation of force by addition and subtraction within ten

1.

Ten ways to remember the formula:

1919 good friend, 2828 hand in hand,

3737 really close, 4646 go together

five five make up a pair of hands. One plus nine, ten little tadpoles,

two plus eight, ten old cks, three plus seven, ten old hens,

four plus six, ten golden monkeys, five plus five, ten big tigers

Add within 10

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extended materials:

master the skills of addition and subtraction within 10

children should keep in mind that "9 to 1", "8 to 2", "7 to 3", "6 to 4", "5 to 5" rounding up ten methods is simple and easy, and the thinking process includes "one look (look at large numbers), two pieces (split decimals), three to 10, four to add" looking at large numbers, dividing decimals, rounding up ten, Add the remainder

start with a simple way to teach children, such as 1 + 1 = 2, 1 + 2 = 3. First use real objects, such as 1 + 1, you can take an apple and an apple, and an apple and two apples, and graally let them deepen the concept of numbers. But the child has no real objects in school, so we teach him to calculate with his fingers

when tutoring children in mathematics at home, the problems should be flexible and diverse, which can arouse children's thinking

How much is 3 + 7? What about 7 + 3? What about 8 + 2? At this time, if you write the question in reverse: which two numbers add up to 10? How many such formulas are there? How to judge that you have finished writing? Is it regular? Let the children find the rule: 0 + 10, 1 + 9, 2 + 8, 3 + 7,..., 10 + 0, and then put forward that the sum of the two numbers is equal to 11? How many formulas are there? Then it is put forward that the sum of two numbers is equal to 100. How many lines can be made out of this formula

these questions can cultivate children's ability to explore mathematical laws. Sometimes, you are busy with housework, but the child asks you to work out a question for him. You can draw a geometric figure on the paper and ask the child to talk about what it looks like? Like drawing a circle, let children imagine. Some children say it's like a big cake; Like a round moon; Like the buttons of mom's beautiful coat and so on. As long as it's round, no matter what you say, the more you say, the better. This can cultivate children's imagination and observation

2. From the practice of children's mathematics teaching, the more scientific teaching steps should be carried out in the following order:
1
it is well known that we should learn to count before we learn to count. However, many parents neglect to use a variety of counting forms to lay the foundation for calculation. Many parents think that their children have learned how to count after they can sing and read 1-100. But in fact, their children have not really established the concept of number and mastered the skills of counting< In fact, there are many contents in counting. In addition to establishing the concept of one-to-one number, there are also many kinds of counting skills. The main forms are as follows:
① n + 1, that is, counting in the order of increasing 1, which is the basis of learning n + 1 calculation
② n minus 1, that is, the number is inverted in the order of decreasing 1, which is the basis of learning n minus 1
3. Count odd numbers and establish the concept of odd numbers< The concept of even number is established< (5) the concept of carry is established for every 10 numbers< It is a very important counting skill to take 5 as a basic unit for every 5 numbers, because 5 is second only to 10 in improving counting and calculating skills
2. To calculate n + 1, children who can count in turn and understand that it means increasing by one in turn can easily learn to calculate n + 1, including 10 + 1, 20 + 1, 99 + 1 and even 100 + 1
3. To calculate n minus 1, children who can count backwards and understand the meaning of decreasing one in turn can learn to calculate n minus 1, including 11 minus 1, 21 minus 1, 100 minus 1 and 101 minus 1
4. Add or subtract the whole 10, such as 10 + 10, 20 + 10,... 90 + 10. Children who can count every 10 and understand the meaning of increasing or decreasing 10 in turn can easily learn
5. Adding or subtracting the whole 5, such as 0 plus 5, 5 plus 5, 10 plus 5 and even 95 plus 5, it is not difficult for children who will count every 5 and understand that it means increasing or decreasing 5
6. Calculate 10 plus N, including 10 plus 1, 10 plus 2... 10 plus 9. Once children understand how much 10 plus is more than ten, they can not only calculate 10 plus N quickly, but also extend to 20 plus N, 30 plus N and even 90 plus n
7. Add two identical numbers, including 1 + 1, 2 + 2... 9 + 9. For children who can count even numbers, when they find that the results of adding two identical numbers are all even numbers, they will easily learn to calculate such problems. Teaching practice found that children generally have spontaneous attention and interest in two questions with the same number added, so children's mastery of this group of questions is often prior to the non-n + 1 questions within 10
8. Calculating the sum of two numbers equal to 10, including 1 + 9, 2 + 8, 3 + 7, 4 + 6 and 5 + 5, the proficiency of this group of questions is very important for more than 10 operations
9. Mental arithmetic (within 20). When children have mastered the above skills, they can do mental arithmetic within 20. Parents should pay attention to remind children to use the calculation skills they have mastered to calculate other problems, such as 2 plus 2 equals 4 and infer 2 plus 3 equals 5, 3 plus 7 equals 10 and infer 3 plus 6 equals 9, 9 plus 9 equals 18 and infer 9 plus 8 equals 17, etc
10. It's not easy for school-age children to calculate the number within 100 by writing (within 100) and by oral calculation. However, after the number is listed in the vertical form, all preschool children with the above skills can complete the calculation with a little instruction, because a two digit addition problem becomes a two digit addition problem after it is listed in the vertical form. At present, about 5-year-old children have learned to write Arabic numerals in kindergartens, so it is completely possible for children of this age to carry out independent vertical operation.

3. The following is the rule of addition and subtraction within 10. It is suggested that parents guide their children to complete their words after finding the rule. Many children know the rule, but they just can't express it clearly. From left to right, the first addend of each line increases by 1 in turn, the second addend decreases by 1 in turn, and remains unchanged. 2. From right to left, the first addend of each line decreases by 1, the second addend increases by 1, and remains unchanged. 3. From top to bottom, the first addend of each column increases by 1 in turn, the second addend remains unchanged, and the sum also increases by 1 in turn. 4. From bottom to top, the first addend of each column decreases by 1 in turn, the second addend remains unchanged, and the sum decreases by 1 in turn. From left to right, the subtracted number in each line of the formula remains unchanged, the subtracted number increases by 1 in turn, and the difference decreases by 1 in turn. From right to left, the opposite is true. 2. From top to bottom, the subtracted increases by 1, the subtracted remains unchanged, and the difference increases by 1. From the bottom up, the opposite is true

4.

one, 10from 内加法口 too 35776:

1+1=2

1+2=3, 2+2=4

1+2=3, 2+2=4

1+3=4, 2+3=5, 3+3=6

1+4=5, 2+4=6, 3+4=7, 4+4=6, 3+4=7, 4+4=8

1+5=6, 2+5=7, 3+5=8, 4+5=9, 5+5=10

1+6=7, 2+6=8, 3+6=9, 4+6=10, 5+6=11, 6+6=12

1+7=8, 2+7=9, 3+7=10, 4+7=11, 5+7=12, 6+7=13, 7+7=14

1+8=9, 2+8=10, 3+8=11, 4+8=12, 5+8=13, 6+8=1 4, 7+8=15, 8+8=16

1+9=10, 2+9=11, 3+9=12, 4+9=13, 5+9=14, 6+9=15, 7+9=16, 8+9=17, 9+9=18

1+10=11, 2+10=12, 3+10=13, 4+10=14, 5+10=15, 7+9=16, 9+9=18

1+10=11, 2+10=12, 3+10=13, 4+10=14, 5+10=15, 6+10=16, 7+10=17, 8+10=18, 9+10=19

10+10=20

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2, from 10 to 2094343;

9-9=0, 9-8=1, 9-strand=2, 9-6=3, 9-5=4, 9-4=5, 9-3=6, 9-2=7, 9-1=8

8-8 =0, 8-7=1, 8-6=2, 8-5=3, 8-4=4, 8-3=5, 8-2=6, 8-1=7

7-7=0, 7-6=1, 7-5=2, 7-4=3, 7-3=4, 7-2=5, 7-1=6

6-6=0, 6-5=1, 6-4=2, 7-5=2, 7-3=4, 7-2=5, 7-1=6

6-6=0, 6-5=1, 6-4=2, 6-3=3, 6-2=4, 6-1=5

5-5=0,5-4=1, 5-3=2, 5-2=1, 5-1=4

4-4=0, 4-3=1, 4-2=2, 4-1=3

3-3=0, 3-2=1, 3-1=2

2-2=0, 2-1=1

1-1=0

5. Starting from 1,
2 can be divided into 1, and (x) 1, 2 and 0
3 can be divided into 1, 2. 2，1 3,0
4 can be divided into 1,3. 2，2 4,0
5 can be divided into 1,4. 2，3 3，2 4，1 5,0
6 can be divided into 5,6. 2，4，3，3 4，2 5，1 6, 0
until 10