3 sixth grade multiplication and division problems, which should not be too simple or too difficult,

1. The downwind transport team transported a batch of goods, the first time it took away 2 5 of this batch of goods, and the second time it transported 1 10 more than the first time, and there were still 40 tons left to be transported. How many tonnes is there in this shipment?

2. There are 300 apple trees in the orchard, and the pear tree is 4 5 of the apple tree and 2 3 of the peach tree. How many peach trees are there in the orchard?

3. The school library purchased 270 English books, which is exactly 1 10 less than the purchased math books, how many more math books than English books?

1.A rectangular open space, 500 decimeters long and 40 meters wide, shrink it to the original 1 100 Draw on the drawing, what is the acre of the rectangular elimination code forest surface on the drawing? Most common mistakes:

If you don't understand the meaning of "shrinking by 1 100", after calculating the area, multiply it by 1 100 and analyze: for example, if you want to reduce our classroom by 1 ...

There are three types of sixth-grade fraction application questions: 1. Find the fraction of a number and use multiplication; 2. Find how many fractions of a number is another number, and use division; 3. Know what the fraction of a number is, find this number, and use division (see textbook).

In layman's terms, division is used to find the fraction and unit 1, and multiplication is used to find the corresponding quantity (comparative quantity) of the fraction.

The key to solving this kind of problem is to first find out the unit 1 accurately, and then find out the fraction corresponding to the comparator, and then determine the calculation method. Here are some examples:

The actual investment is 37.6 million yuan, which is 1 9 less than the plan, how many yuan is the planned investment?

Analysis: Find a ...... in the questionLess (more) is followed by the ,...... of the scoreis Unit 1. Therefore.

Planned investment (corresponding to Unit 1

Planned Investment- Actual Investment corresponds to 1 9

Actual investment (37.6 million yuan) corresponds to 1-1 9

Column: 3760 (1-1 9).

This kind of problem is best to draw a line diagram to show it intuitively, it is easier for students to accept, I have just started to contact the Internet, I can't show it here, I'm sorry, I'm smiling. Good luck with your work.

The key is unit 1

If unit 1 is known, it is usually calculated by multiplication.

If you find the unit 1, it is usually calculated by division.

Fraction multiplication and division application problem solving tips:

1. Grasp the key sentence (sentence with score);

Second, find the unit "1" (at the same time mark the score corresponding to the comparison amount);

3. Determine the quantitative relationship.

1) Knowing the quantity of the unit "1", find the quantity corresponding to the fraction (comparative quantity), and use multiplication;

Knowing the quantity corresponding to a fraction (comparative quantity), find the quantity of the unit "1", and use division.

Comparison Quantity The fraction corresponding to the comparison quantity. 】

The two upstairs don't know if they have taught primary school mathematics, one is to practice more, and cultivate children's problem-solving ability and thinking ability in practice, and the other is to use relations to decide whether to use multiplication or division in application problems.

For example: time * speed = distance, of course, to find the distance is to use multiplication, to find time and speed of course should be to use division.

There are many more such relationships.

Find unit one, unit one is known to use multiplication, unknown use division.

Just a few words, the known unit uses multiplication, and the unknown unit uses division.

1. Multiplication. Knowing the unit "1", finding what is the fraction of the unit "1" is done by multiplication.

2. Multiplication and addition. Knowing what the unit "1" and the number of fractions more than the unit "1" are, multiply the specific number of the unit "1" by the sum of the unit "1" and the number of fractions more.

3. Multiplication and subtraction. Knowing what the unit "1" and the number less than the unit "1" are, multiply the specific number of the unit "1" by the difference between the unit "1" and the lesser fraction.

4. Division. If you know what fractions of the unit "1" are, find the unit "1", divide the specific number of the unit "1" by the fraction of the corresponding unit "1".

5. Division and addition. Knowing what is a fraction of a fraction more than the unit "1", find the unit "1" and divide the number a fraction more than the unit "1" by the sum of the unit "1" and the fraction more than the unit "1".

6. Division and subtraction. Knowing what is a fraction of a fraction less than the unit "1", find the unit "1" and divide the number a fraction less than the unit "1" by the difference between the unit "1" and the fraction less than the unit "1".

7. In short, if you know the number of the unit "Oak and 1", and find another number related to the unit "1", use multiplication; If you know what fractions of the unit "1" are, find the unit "1" and use division.

The sum of the first two days accounts for 1 3 + (1-1 3) * 2 3 = 7 9, then the third day uses 1-7 9 = 2 9

Total amount of oil = 6 (3 7 * 7 9-2 9) = 54 kg barrel weight 58-54 = 4 kg.

Used x 3 on the first day

The next day I used 2 3*2 3*x

On the third day, it was used (x 3 + 2 3 * 2 3 * x) * 3 7-6 and the three days were added to (x 3) + (4x 9) + (x 3-6) = x to get x = 54, so the barrel weight was 58-54 = 4 kg

Day 2: (1 1 3) 2 3 4 9

Weight of oil: 6 [1 3 4 9 (1 3 4 9) 3 7 1] 54 (kg).

Weight of the barrel: 58 54 4 (kg).