Chapter 1 Division (with remainder division).
1. The name of each part of the division equation.
23÷4=5……3 23 is the dividend, 4 is the divisor, 5 is the quotient, and 3 is the remainder.
2. In the division formula with remainder, the remainder must be smaller than the divisor, or it can be said that the divisor must be larger than the remainder.
For example, if there is a remainder in mouth 7, the maximum remainder is (6), and the remainder is required to be less than the divisor 7.
In mouth 5 = 6 ......, the remainder is maximum (4). The remainder is required to be less than the divisor of 5.
3. In the application problem, the units of the divisor and the remainder are determined according to the problem, the unit of the quotient is the same as the unit of the problem, and the unit of the remainder is the same as the unit of the dividend.
4. Solve life problems, such as asking the question "How many boats do you need at least?" "Use the "one method (plus 1 with quotient)".
Example: There are 22 people, each boat is limited to 4 people, how many boats should be rented?
22 4=5 (strips) ......2 (pcs).
5+1=6 (strips).
A: A minimum of 6 boats are required to be rented.
5. If the question is "How many clothes can you make at most?" "Quotient as the final answer.
For example, if you need to use 3 meters of flower cloth to make a set of clothes, how many sets of clothes can you make with 25 meters of flower cloth?
25 3=8 (sets) ......1 (m).
A: You can make up to 8 sets of clothes.
6. Calculate the number of parts with the remainder division formula.
Example: (51) 6=8......3
Count 6 8=48 first, then 48+3=51.
Calculate 7 6=42 first, then 42+5=47.
Calculate 51-3=48 first, then 48 8=6.
Count 26 2=24 first, then 24 4=6.
Chapter 2 Direction and Location (Knowing Direction).
1. The map is drawn according to: up (north), down (south), left (west), right (east).
2. When identifying the direction, it is necessary to identify the center point. Example: "Kitten in a puppy ( ?) square", the center point is the puppy.
3. The sun rises (east) and sets (west) every morning.
4. The compass points to the (south) side at one end and the (north) side with the other.
5. Get up in the morning, the front is (east), the back is (west), the left is (north), and the right is (south).
6. The annual rings of large trees are sparse towards the (south) side, and the denser ones are towards the (north) side.
7. The north wind blows from (north) to (south), and the southwest wind blows from (southwest) to (northeast).
8. Steering board:
Find out first: up north, down south, left west, right east.
Re-determine: Northeast (the part between east and north) Northwest (the part between west and north).
South-East (the part between east and south) Southwest (the part between west and south).
Chapter 3 Big Numbers in Life (Knowing Numbers Within 10,000).
1. The first digit is (one) digits, the second digit is (ten), the third digit is (hundred), the fourth digit is (thousand), and the fifth digit is (10,000) digits; To the left of the thousand is (10,000) and to the right is (hundred).
2. The highest digit of a four-digit number is (thousand); Its thousand digits are 5, the single digit is 2, and the other digits are 0, which is (5002).
3. In 8536, 8 is in the (thousand) position, which means (8 thousand); 5 in the (hundred) digit means (5 hundreds).
3 in the (ten) digit, which means (3 tens); 6 in (pcs) digits, which means (6 ones).
4. The number composed of 3 thousand and 5 tens is (3050), which is a (four) digit;
When reading, start from the high position, with one or two "zeros" in the middle, and only one "zero" in the middle; No matter how many "zeros" there are at the end, don't read them; When writing numbers, start from the high position, write in the order of digits, and write "0" to occupy the place if there is no number in the middle or at the end.
Ten is (one hundred), 10 hundred is (one thousand), 10 thousand is (ten thousand), 6, the largest three digits are (999), the smallest three digits are (100), the largest four digits are (9999), and the smallest four digits are (1000).
7. When comparing the size, compare the number of digits first, the number with more digits is larger, and the number with fewer digits is small; When the number of digits is the same, the comparison starts from the highest digit, and the number on the highest digit is the same, and the next digit is compared until the comparison is larger. "From large to small" > "from small to large".
Chapter 4 Measurement
1. Millimeters (mm), centimeters (cm), decimeters (dm), meters (m), and the advance rate between adjacent units is "10".
m = 10 dm, 1 dm = 10 cm, 1 cm = 10 mm, 1 m = 100 cm, 1 dm = 100 mm, 1000 m = 1 thousand.
3. To compare the size of the length unit, the unit must be observed first, and then it can be compared after replacing it with a unified unit;
4. Conversion of length units (1.)Add 0 and subtract 0. 2. The advance rate is a few plus or minus a few 0s).
Chapter 5 Addition and Subtraction
1. When orally calculating the addition and subtraction of integer hundreds, think of adding and subtracting several hundreds, and the arithmetic of adding and subtracting integer tens is also the same.
2. Pay attention to the following when calculating: The same digit should be aligned, starting from the single digit.
2) When calculating addition, which digit is added to the full ten, to the previous digit "advance one", do not forget to add the carry 1 when calculating the previous digit;
When calculating subtraction, when which digit is not enough to subtract, you should "borrow 1" from the previous digit, and don't forget to subtract the debit 1 when calculating the previous digit;
3. Addition + addition = and
One plus = and one another plus number.
For example: ( 156 = 368
4. Minus - minus = difference
Subtracted = minus + poor
Subtraction = subtraction is one difference.
For example, ( 156-368 (Finding the Subtracted Numbers: Calculated with 156+368).
980- (=760 (Subtraction: 98d760).
5. The calculation method of addition: use and subtract one of the additions to see whether the difference is equal to the other addition;
The calculation method of subtraction: add the difference with the subtraction to see if the result is equal to the subtracted number.
Note: Do not copy the wrong number during the calculation, and do not copy the calculation results directly. ）
Chapter 6 Getting to Know the Corner
1. The angle is composed of (1) vertices and (2) edges;
2. According to the size of the angle, the angle is divided into (sharp) angle, (right) angle, (blunt) angle, and all right angles are (equal).
Smaller than a right angle is a (sharp) angle, and larger than a right angle is a (blunt) angle.
To know what angle an angle is, you can compare it with the right angle on the triangle.
3. Pay attention to the size of the angle when comparing it:
The size of the angle is not related to the (length) of the edge, but to the (opening size) of the angle, and the larger the opening, the larger the angle.
4. The square has four (right) angles, and all four sides are (equal).
5. The rectangle has four (right) angles, and the opposite sides of the rectangle are (equal).
6. The parallelogram has (4) sides, 2 (sharp) angles, 2 (blunt) angles, opposite sides (equal), opposite corners (equal).
Chapter 7 Hours, Minutes, and Seconds
1. There are (12) large grids on the clock face, and each large grid has (5) small grids, and there are (60) small grids in total;
2. It is 1 second for the second hand to walk a small grid, 5 seconds to walk a large grid, and 60 seconds to walk a circle, which is 1 minute;
3. It is 1 minute to walk a small grid on the minute hand, 5 minutes to walk a large square, and 60 minutes to walk a circle, which is 1 hour;
4. It takes 1 hour to walk a large block of the hour hand and 12 hours to walk a circle;
5. The advance rate of adjacent units of hours, minutes and seconds is 60;
1 hour = 60 minutes, 1 minute = 60 seconds.
6. Compare the time, first of all, observe, and then compare the size after the unit.
Accurate time to read out the surface.
Look at the hour hand first, how long the hour hand has passed is what time;
Looking at the minute hand again, the minute hand has gone a few small squares is a few points.
8. The addition and subtraction of time: when the minutes are not enough to subtract, it is necessary to borrow 1 from the previous one, turn it into 60, and then add and subtract.
9. Elapsed time = end time, start time.