Appendix+Appendix = Sum

Sum = Appendix+Appendix

Addendum sum = another addend

Another addend = and-addend

The position and sum of commutative addends remain unchanged.

Second, subtraction.

Negative-negative = difference

Difference = minuend-minuend

Negative difference = negative

Subtraction = minuend-difference

Difference+Minus = Minus

Negative = negative+difference

Third, digitalization.

1, the first digit of a number from the right is a single digit (indicating several ones), the second digit is a tens digit (indicating several tens), and the third digit is a hundred digits (indicating hundreds).

Two out of 2 and 20 10, or 20 out of 20 1.

3. 10 has 1 tens, or 10 has 10 ones.

4. Reading and writing are too high to be cold. Reading is writing words, and writing is writing math words.

5. Write math words in front of each word and language words behind each word.

Fourth, column calculation

Below "︸" is the total, and (+) is calculated by addition.

"︸" is the search part above, and (-) is calculated by subtraction.

5. What is the specific size?

Find how much a large number is more than a decimal, and work out (-) by subtraction.

Find how much the decimal is less than the large number, and work out (-) by subtraction.

Sixth, know the time.

1, short hour hand and long minute hand. 1 hour = 60 minutes 60 minutes = 1 hour 1 minute = 15 minutes.

2. When the minute hand points to 12, it is the hour, and the hour hand points to the number, it is the time.

3. When the minute hand points to 6, it is half hour, and when the hour hand crosses the number, it is half hour.

There are twelve numbers on the clock face. There are five squares between two numbers, and there are sixty squares in a week.

5. When an hour hand turns a number, it is an instant, and when the minute hand turns a square, it is a minute.

6. When the hour hand just passes the number, it means how long.

Seven, gather together ten songs

Make up ten songs: children clap their hands. Let's sing ten songs. Nine equals one, eight equals two, seven equals three, six equals four, and two or five equals ten.

Ten-fold method: divide the decimal and round the large number. Divide large numbers into decimals

Eight, = equal sign fishing number

The big mouth faces the large number and the pointed end faces the decimal number.

The big mouth is bigger than the sign on the left and smaller than the sign on the right.

Both sides are equal, with equal sign.

Nine, graphic application problems

Find out the known conditions and problems first, and then decide to calculate by addition and subtraction.

Find out what * * * is and add it. (+)

Find out what is left, what is left, how much is left, and work it out by subtraction. (-)

X. Understanding RMB

1 yuan = 10 angle 1 angle = 10 point 1 yuan = 100 point.

Eleven, know the location

Head up, feet down, chest, back, left hand press, right hand write, walk up and down stairs to the right, the position can't be wrong.