The fifth grade mathematics is an important stage for students to learn. Mastering some simple calculation methods and skills is very helpful to improve your mathematical operation ability. This paper will introduce some simple mathematical calculation methods and skills suitable for grade five students.

First, the methods and skills of addition calculation

1, decomposition method: decompose a large number into easy-to-calculate numbers, and then add them. For example, 34+56 can be divided into 30+4+50+6, and then added one by one to get 80.

2. Carry method: When the number of digits added by two numbers exceeds 10, add the carried number to the ten digits. For example, to calculate 27+35, first calculate 7+5= 12, then add the carried 1 to 2 to get 2+ 1=3, and finally get 62.

3. Interval addition: divide a large number into several groups from left to right according to the number of digits, and then add the numbers of each group. For example, the calculation of 456+789 can be divided into three groups: 400+700, 50+80, and 6+9, and then added separately to get 1 150.

Second, the methods and skills of subtraction calculation

1. Borrowing method: When a bit of the minuend is smaller than the corresponding bit of the minuend, it is necessary to borrow from a higher bit. For example, to calculate 78-35, first calculate 8-5=3, and then change it from ten digits to 7-3=4, so the result is 43.

2. decomposition method: divide a large number into easy-to-calculate numbers and then subtract them. For example, the calculation of 78-35 can be divided into 70-30+8-5, and then subtracted one by one to get 40+3=43.

3. Interval subtraction: divide a large number into several groups from left to right according to the number of digits, and then subtract the numbers in each group. For example, the calculation of 789-456 can be divided into three groups: 700-400, 80-50, 9-6, and then subtract them respectively to get 300+30+3=333.

Third, the methods and skills of multiplication

1, decomposition method: divide a large number into easy-to-calculate numbers, then multiply them, and then add the results. For example, calculating 23×5 can be divided by 20×5+3×5, and then added to get100+15 =115.

2, 99 multiplication formula: recite the 99 multiplication formula table, you can quickly calculate the product of two numbers. For example, if we calculate 8×6, we can know that the result is 48 according to the formula table.

3. Commutation law: multiplication satisfies the commutation law, that is, a× b = b× a, so the positions of two numbers can be exchanged as needed in the calculation, which makes the calculation easier. For example, if 8×6 is calculated, the exchangeable position is calculated as 6×8, and the result is still 48.

Fourth, the calculation methods and skills of division

1, decomposition method: decompose a large number into easy-to-calculate numbers, and then divide them. For example, the calculation of 56÷8 can be divided into 50÷8+6÷8, and then divided one by one to get 6+0.75=6.75.

2. The reciprocal rule of division: when the divisor is in the form of 10, 100, 1000, etc. , you can directly move the dividend to the left by the corresponding number of digits to get the result. For example, if you calculate 420÷ 10, you can directly shift the dividend to the left by one bit to get 42.

3. the law of division of multiple numbers: when the dividend is a multiple of the divisor, the quotient is an integer. For example, calculate 420÷7. Because 420 is a multiple of 7, the quotient is 60.

The above are some simple calculation methods and skills commonly used in fifth grade mathematics. Mastering these methods can improve the speed and accuracy of calculation and help students solve mathematical problems better. Of course, besides these methods, there are many other methods and techniques. I hope students can explore and summarize in their study and improve their mathematical operation ability.