1/2+ 1/3= 1/3× 1/4= 1 1/2-0.5= 1/ 12×6/5=

3/5× 1/3= 6÷ 1/2= 8/9÷7/8= 5/4×4/5=

5- 1/7= 5/4÷4/5=

fill (up) a vacancy

1、 1/7×( )= 1/7÷( )= 1/5×( )= 1/4÷( )= 1

2. A project needs 8 hours for Party A and 10 hours for Party B.. The time ratio used by both parties is (), and the efficiency ratio of both parties is ().

3. 15×3/4 means (), and 4/5×5 means ().

4. 3/5 of the number A is equal to the number B, and the unit "1" is ().

5. The number A is 4/5 of the number B, and the ratio of the number A to the number B is ().

Third, to judge whether it is true or not, type "√" and type "×" wrongly.

1, because the reciprocal of 3 is 1/3, the reciprocal of 0 is 1/0. ( )

2.A is 1/5 of B, and B is five times that of A ... ()

3. Because 1/5×8. And 8× 1/5 have the same result, and there is no difference. ( )

When two fractions are divided, the quotient must be greater than the dividend. ( )

5. 2/3 of A is equal to 1, which means to look at the unit "1". ( )

Fourth, simplify the following ratios

1/2 : 1/3= 0. 15 :3= 36 :24=

0. 1 :0.0 1= 6.3:0.9=

5. Column calculation.

1. A number 1/3 is 5 more than its 1/4. What's this number?

2. 3/4 plus 3/4 of a number and the sum is 1. What is this number?

3. The sum of1/3 plus 1/4 is equal to 3/4 of a number. What's this number?

Sixth, calculation.

(1), X.

5/9×x=5/6 x÷ 1/2=2/3

4x- 1 1/2 = 7 5/8÷x = 1/2

(2) Calculation: (Simple calculation is required)

3/4×2/5+3/4×3/5= (8 2/5- 10 1/2×4/5)÷2/5=

24 7/8- 1 1 2/7-9 5/7= 1÷〔 1/5+(5/6-3/8)×4/ 1 1〕=

18-2 2/ 15÷(3 19/2 1+ 1 3/7)= 8 4/5+4 2/3×2 3/7÷3 1/3=

Sixth, the application problem.

1.A has traveled 3/8 of the way from A to B, and it is still 45 kilometers away from the center. How many kilometers is it between A and B?

The output value of a factory in September this year is 4/5 of that in 10. It is known that the output value of 10 is 2 million. What is the output value in September?

3. A ship sails from Port A to Port B at a speed of 42km/h, arrives in 6/7 hours and returns in 3/4 hours. How many hours do you drive on average per hour?

4. A canteen brought back a batch of rice. On the first day, it used 250 kg, the next day it used 230 kg, and in two days it used 3/5 of the total. How many Jin of rice did the school bring back?

There are 297 apple and peach trees in the orchard. Peach trees are 4/5 of apple trees. How many peach and apple trees are there? (multi-faceted solution)