1, integer percentage divided by one digit; 2, there is a division of 0 in the middle of the quotient; 3. Division with 0 at the end of quotient; 4. Simple application.

1 [Memory] When three digits are divided by one digit, the quotient may be two digits or three digits. (The quotient is three when hundreds are divided enough, and two when hundreds are not divided enough. )

There is a division of 0 in the quotient of 2[ memory]. When ten digits are not enough to divide, you must ask for a quotient. )

3[ Memory ]0 times any number equals 0. 0 divided by any number that is not 0 equals 0.

4 [continued application questions].

5 [half price sale] (original price ÷2= current price)

6. Memory relationship: total number of chickens ÷ number of layers = total number of books per layer ÷ number of shelves = number of books per layer.

Total number of batteries ÷ number of batteries per box = number of boxes speed × time = distance distance ÷ time = speed distance ÷ speed = time.

The total number of skipping rope ÷ a few minutes = the number of jumps per minute ÷ the total workload ÷ working time = working efficiency.

Typing times = Typing times per minute

Unit 2 Year Month Day

[Knowledge points in this unit]:

1, know big month, small month, normal year and leap year; 2. Calculate the number of days that have passed; 3. Happy birthday

1[ Memory] years are divided into normal years and leap years; Month is divided into big month, small month and special February. There are 365 days in a normal year and 366 days in a leap year. (The big months are: 65438+ 10, March, May, July, August, 65438+ 10, 65438+February (7); Abortion: April, June, September, 165438+ October) (4)

February in a normal year has 28 days and February in a leap year has 29 days.

There are July and August in succession, or 65438+February and 65438+ 10 month. The number of days in two consecutive months is 6 1 day, one of which is a big month and the other is a small month.

Average year 1 Q2 Q3 Q4

Days 90 9 1 92 92

First half 18 1 day, second half 184 days.

4、

Average year 1 Q2 Q3 Q4

Days 9 1 9 1 92 92

First half 182 days, second half 184 days.

5. Various festivals: New Year's Day 65438+1 October1,Arbor Day1March, International Labor Day1May, International Children's Day1June, Army Day1August, Party.

6. Usually there are three normal years and 1 leap year every four years. The Gregorian calendar year is a multiple of 4, usually a leap year. Gregorian calendar year is an integer, and it must be a multiple of 400 to be a leap year (AD 800, 1200, 1600, 2000, 2400, etc. ).

7. Memory: People's Republic of China (PRC) was founded in 1949, 10, 1, and 2008 will be the 59th anniversary. (2008- 1949=59)

8. Calculate the number of days [by month], such as how many days are from June 12 to August 17?

June, July, August

think

Kao 12-30 No.3 1 No.65438+7.

30-12+1=19 days 3 1 day 17 days.

Total:19+31+17 = 57 days.

Unit 3 Translation and Rotation

[Knowledge points in this unit]:

1, Understanding Translation and Rotation 2, Beautiful Lace

Note: The shape and size of the object remain unchanged after translation. The movement of a pendulum is rotation.

Unit 4 multiplication

[Knowledge points in this unit] 1, two digits multiplied by integer ten, two digits multiplied by two digits for calculation, and three digits multiplied by two digits for estimation. 4. apply.

[Memory] 1, the product of two digits multiplied by two digits may be three digits or four digits. 2. Check the calculation: swap the positions of the two multipliers.

★ multiplication application problem. Question 6 on page 38, question 4 on page 39 and so on.

Quantitative relationship: number of bottles of milk per box × number of boxes = number of bottles of milk; Unit price × quantity = total price.

Unit 5 Observing Objects (omitted)

Unit 6 kilometers and tons

1, length unit: mm, cm, decimeter, meter and kilometer. Entry rate:1km =1000 m.

Quantitative formula: the length of a runway coil × the number of laps = the running distance.

2. The units of mass are grams, kilograms and tons. The output is 1 ton = 1000 kg.

3. Unit conversion. Large units are converted into small units (multiplied by the forward speed between them), and small units are converted into large units (divided by the forward speed between them).

Unit 7 Axisymmetric Graphics

1. The figure whose left and right sides completely overlap after being folded in half is an axisymmetric figure.

2. Common axisymmetric figures are: rectangle, square, circle and equilateral triangle.

3, the letters are axisymmetric figures: A, B, C, D, E, H, I, K, M, O, T, V, U, W, X, Y.

4. Draw the other half of the axisymmetric figure according to its half.

Unit 8 Cognitive Score

1, cell "1"-one object or several objects.

2. Score: divide an object or several objects into several parts, which means 1 or several parts.

3. Addition and subtraction of fractions with the same denominator. (The denominator remains the same, and the numerator is added and subtracted. )

4. Total number ÷ denominator × numerator = number taken out. For example, what are three fifths of 90 peaches?

5, the numerator is the same, and the score with small denominator is large. The denominator is the same, and the fraction with large numerator is large.

6. Class 3 (1) has 20 boys and 25 girls. The number of boys accounts for the number of girls and the number of boys accounts for the number of students in the class.

Unit 9 Area of Rectangle and Square

1, formula: (see table)

2. A square with a side length of 1 cm and an area of1cm 2; A square with a side length of 1 decimeter and an area of 1 square decimeter; A square with a side length of 1 m and an area of 1 m2.

Rectangular regular square

Area length x width = area side length x side length = area

Perimeter (length+width) ×2= perimeter ×4= perimeter.

Lateral area ÷ Length = Width

Area/width = length

Perimeter ÷2- Length = Width

Perimeter ÷2- Width = Long Perimeter ÷4= Side Length

3. Area unit propulsion rate: 1 square decimeter = 100 square centimeter 1 square meter = 100 square decimeter.

4. Convert large units into small units (multiply the ratio between them)

Small units are converted into large units (divided by the ratio between them)

5, ★86 pages of thinking questions (hands-on points)

6、

The area of Figure A is larger than that of Figure B ... but their perimeters are equal.

7. The units of length unit and area unit are different and cannot be compared.

8. Make a rectangle with 20 sticks. What is its circumference and area? Make a rectangle with 20 small squares, and the side length is 1 cm. What is its circumference and area? (The two situations are different)

Unit 10 Statistics

1, the method of finding the average is: 1, shift more and make up less by 2, and total number ÷ number of people (copies) = average.

2. Exercise and physical changes. After exercise, people's pulse will accelerate. After a few minutes' rest, it will return to normal.

Unit 1 1 Understanding decimals

1, a few tenths equals a few tenths. 2. How to read and write decimals? 3. Comparison of decimal size. 4. Addition and subtraction of decimals.

5,0 is both a natural number and an integer. 6. Decimals are not necessarily smaller than integers.