Knowledge points of mathematics in the first grade of primary school
Fifth unit
I. Understanding of 6- 10:
1, Count: According to the number of objects, it can be represented by a number of 6- 10. When counting, counting from front to back is from small to large.
2. Number sequence in10:
(1) From beginning to end: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
(2) From back to front: 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.
3. Compare size: In the order of numbers, the number behind is always greater than the number before.
4. ordinal meaning: used to indicate the order of objects, that is, which one.
5. Composition of Numbers: A number (except 0, 1) can be composed of two smaller numbers. For example, 10 consists of 9 and 1
When remembering the composition of numbers, one group of numbers can be used to associate another group of numbers in different positions.
Addition and subtraction of 2.6- 10
Calculation method of addition and subtraction within 1 and 10: according to the composition of numbers.
2. Figure 4: According to different thinking angles of a picture, two addition formulas and two subtraction formulas can be written.
3. There is a question mark under the "braces", which requires the two parts to be merged and calculated by addition. There is a question mark on the upper side of the "brace" to find out how much is left in the total and calculate it by subtraction.
Third, increase and decrease.
1. Calculation method of continuous addition: When calculating continuous addition, it should be done from left to right, first calculate the sum of the first two numbers, and then add it to the third number.
2. Calculation method of continuous subtraction: When calculating continuous subtraction, proceed from left to right. First calculate the difference between the first two numbers, and then subtract the third number from the obtained number.
Fourth, add, subtract and mix.
Calculation method of addition and subtraction: the calculation is carried out from left to right. First, add (or subtract) the first two numbers, and then subtract (or add) the third number.
Senior one mathematics knowledge points
Unit 7 Addition and subtraction (2)
(Understanding of the number 1 1 ~ 20)
1, the method of counter representing number is the simplification and abstraction of the method of putting a stick to represent number;
The "ten digits" of the number on the counter correspond to "bundle" and "one digit" corresponds to "root". This abstraction forms an extremely important concept of bit value.
2. Know a new counting unit "ten" and know that "from the right, the first number is one and the second number is ten."
3. In the activities of posing, counting and tying a bundle, recognize the students to recognize, read and write 1 1 ~ 20. Master the order, size and combination of numbers within 20.
(More than ten addition and subtraction (subtraction) numbers)
1, using image building blocks to help students understand addition without carry and subtraction without abdication. (that is, on the original basis, it is added and reduced to subtraction. )
2. Learn not to carry addition or abdicate subtraction within 20 years. The calculation method is to add and subtract from single digits first, and then add and subtract from ten digits.
3. Find the law in the calculation and understand the number exchange position on both sides of the plus sign in the addition, and the addition result remains unchanged. In subtraction, the minuend is a constant, and the larger the minuend, the smaller the difference.
(carry plus 9 plus a few)
1. Let students learn "9+?" By solving problems. Carry addition.
2. Understand the simplicity of the ten-point method. (Another addend added to 9 is decomposed into 1 and several numbers, so that 9 and 1 constitute 10, and then 10 is added to the remaining numbers, which is "9+?" Ten points method.
3. Directly calculate the formula of carry addition as consolidation exercise.
(carry plus 8 plus a few)
1, guide students to use the existing "9+?" Experience of exploring "8+"? Calculation method of.
The first method: 10 plus 8 to decompose another addend.
The second method: decompose 8 and add an addend to 10.
2. Further understand the "ten-point method".
3. Calculate 8 plus a few correctly and skillfully.
(Reduce abdication from ten to several (one))
1, learn the abdication subtraction of "ten minus nine".
2. Let students explore and learn the abdication subtraction of "ten MINUS eight" and related mathematical problems.
3. Experience the diversity of calculation methods.
The first method: if the number in the unit is not enough to subtract 9 or 8, subtract 1 from 10, and then add 10 to the unit and subtract it.
The second method: decompose a dozen into 10 and several, and subtract 9 or 8 from 10, and then add the result to another number.
The third method: reverse thinking, subtraction and addition, 9(8) plus a few equals a dozen, and a dozen MINUS 9(8) equals a few.
The fourth method: subtracting 9 from a dozen can be considered as adding 1 to a single digit. (If you subtract 9 from a dozen, you can add 1. )
The above methods do not require all students to master, but require students to clearly understand the arithmetic of abdication subtraction.
(Subtraction of abdication among more than a dozen subtractions (II))
1, correctly calculate the subtraction of more than ten numbers such as negative 7 and negative 6. (subtraction of 5, 4, 3, 2, etc. Is interspersed in the actual teaching situation. )
2. Further perceive the diversity of problem-solving strategies.
(solving problems)
1, learn to solve simple practical problems with mathematical knowledge.
Merge carry addition and abdication subtraction within 2.20.
3. Ask students to write two subtraction formulas according to an addition formula.
4. Understand a number from multiple angles and establish a sense of number.
For exercises:
8+ 1= 0+ 10= 12+7= 17+7=
7- 10= 3- 13= 19- 15= 17+ 1 1=
4+6= 14+2= 1+ 15= 18- 19=
17+ 15= 9- 16= 0+ 19= 15+8=
5+6= 8+ 1 1= 3+ 14= 14+2=
8+ 10= 15+ 18= 8+ 1 1= 15+4=
1-8= 0+7= 15+ 17= 17- 1=
Knowledge points of mathematical addition and subtraction in the first volume of the first grade of primary school
Addition and subtraction (1)
Add up two numbers. Appendix+Appendix = Sum
For example, 3+13 = 16,3 and13 are addends, and the sum is16.
Take a part from a number and find out how much is left. Subtract. Negative-negative = difference
For example, 19-6= 13, 19 is the minuend, 6 is the minuend, and the difference is 13.
(1) Memorize the numbers of addition and subtraction in the table.
(2) Understand the following rules
1, addition
(1) Add two numbers and keep the number unchanged: if one of the two added numbers increases, the other decreases, the other increases and the other decreases.
(2) When two numbers are added, one of them remains the same. If the other number changes, this number will also change, and the change of the result is as big as the change of the addend.
(3) Add the two numbers and exchange positions to get the same number.
Step 2 subtract
(1) Subtract one number from another to keep the reduction unchanged: if the minuend increases, the result will also increase, and the result will increase as much as the minuend increases; When the minuend is reduced, the result is also reduced, and the result is also reduced by how much the minuend is.
(2) Subtract one number from another to keep the minuend unchanged: the meiosis increases, the result decreases, and the meiosis increases and the result decreases; If meiosis decreases, the results increase, and the results increase by how much meiosis decreases.
(3) When one number is subtracted from another, the number remains the same: the minuend increases as much as it increases; As much as the minuend is reduced, the minuend will also be reduced.
Related articles on the arrangement of knowledge points in the first volume of mathematics in grade one;
★ Knowledge points of the first volume of mathematics in Grade One of People's Education Edition
★ Learn the knowledge points of the first volume of mathematics in senior one.
★ The key arrangement at the end of the first volume of the first grade mathematics.
★ Formula of mathematical concepts in the first volume of senior one.
★ Knowledge points of mathematics in the first grade of primary school
★ Summary of the final knowledge of the first volume of mathematics in grade one.
★ Outline of Mathematics Review for the First Volume of Senior One.
★ Knowledge points of the first three units in the first volume of senior one mathematics.
★ Induction of knowledge points in the first volume of junior high school mathematics.
★ Summary of knowledge points in the last four units of mathematics in grade one.