First of all, "SJ" is right and smart:

1. Numbers written directly:

×2 = × 1 = ×= 12×= ×7= ×=

5-= ×= +×=

2. Use your favorite method to calculate:

+× ×+× +++

×× (+)×4×5 27×- 1 1

10 1×- ×48 ×34×7×

3. Formula calculation

How much is (1)? (2) What is the sum of the differences between sum and their products?

(3) What's the difference between and? (4) What is the product of the sum of 9 multiplied by its reciprocal?

Second, fill in the "corresponding seat"

(1) x 7 stands for (); 8× means ().

(2) hours = () minutes, kilograms = () grams.

1 m2 = () square decimeter = () decimeter

(3) The reciprocal of the smallest prime number is (), the reciprocal of 0.25 is (), and the reciprocal of is ().

(4) The number of boys in the sixth grade is the number of girls, so the number of boys accounts for the whole grade.

5] A pile of sand weighs tons, used up, used up () tons, and there is a total.

[6] Fill in ""or "=" in ○.

×××××××5m× 1m

(7) There are as many peach trees in citrus reticulata, and () is regarded as the unit "1". If there are 28 orange trees, there are () peach trees.

Being a batch of parts can be completed in 4 hours, then () hours can be completed.

⑼ ×( )=×( )=-( )=( )×0.3 = 1

At the beginning of the new semester, students should choose a squadron leader. Of the ***60 people who participated in the election, Xiao Ming was elected, Hong Xiao was elected, and Xiaodong was elected, with the least votes respectively () and ().

⑾ As shown in the figure, it is a pile of disks. If one of them is painted red, it needs to be painted red () disc; If you take away 4 discs and paint the rest in red, you need to paint () discs in red.

⑿ It is known that a× = b× = x c, where a, b and c are natural numbers, and none of them are natural numbers. Let's put the three numbers A, B and C in descending order: ()