1, 2/5 (5) times 2.

2, 6 kilometers (2/3) is 4 kilometers.

3、 1/5÷( 1/5)= 1/4÷( 1/4)= 1/3÷( 1/3)= 1/2÷( 1/2).

4, 4/5 tons of soybean can squeeze out 7/25 tons of oil, to squeeze out 1 ton of oil, you need (20/7) tons of soybean, and one ton of soybean can squeeze out (7/20) tons of oil.

5. A 2-meter-long rope is cut into 5 sections on average, each section is (2/5) meters long, and each section belongs to this rope (1/5).

6. To make 100 parts, make 3/ 10 parts every day and make (90) parts every three days.

7, 6÷3/5 means (know that the product of two factors is 6, one of which is 3/5, and what is the other factor).

Select:

1, there are 20 pens in black and blue, and their number ratio may be (c).

a、7:4 B、3:4 C、3:2 D、2:5

2.36/2 1 contains (a) 2/7.

a、6 B、7 C、8 D、9

Calculation:

1、 17× 1 1/23+ 17÷23/ 12

= 17× 1 1/23+ 17× 12/23

= 17×( 1 1/23+ 12/23)

= 17× 1 = 17

Application:

1, and the weight ratio of two baskets of pears is 5: 3. Take out 12kg from the first basket and put it in the second basket, which means that the second basket has 8kg more pears than the first basket. How much do these two baskets of pears weigh?

2. Party A has more deposits in the bank than Party B by 560 yuan. Party A took out 1/6 of its own deposit for the first time and 200 yuan for the second time. At this time, Party A has more deposits than Party B 120 yuan. What are the deposits of Party A and Party B?

3. Runfa Supermarket sells beer. The ratio of cases sold in August to cases sold in July is 4: 5. 180 cases sold in August. How many boxes did you buy in July?

4, the size of the two bottles of oil * * * weighs 2.7 kilograms. After using 0.2 kg of oil in the big bottle, the weight ratio of the remaining oil to the oil in the small bottle is 3: 2. How many kilograms of oil are in the big bottle and the small bottle respectively?