Primary school math Olympiad questions, which require the column formula method

Both are booked for the whole class:

Second prize: 3 5 + 9 10-1 = 1 2

1st prize: 3 5-1 2=1 10

3rd prize: 9 10-1 2=2 5

Overage: 5 9 + 2 3-1 = 2 9

Soil: (1-1 3-1 5) 30 = 14 people.

Xiaoxiao reads this book every day 1 5

4 of 4 days to read this book 5

Average daily reading: 75 5 = 15 pages.

The difference between the original numerator and denominator: 71-3=68

Add the same number at the same time, and the difference is still 68

After reduction, the difference between the numerator and the denominator is: 5-1=4

Before the approximation, the numerator was: 68 4=17

The number added is: 17-3=14

1.In Class 5 (1), 4 out of 7 students ordered "I Love Mathematics" and 5 out of 14 students ordered "The Story King", and 11/14 of the students ordered both kinds of reading materials, and how much of the class ordered both kinds of reading materials?

2.The school holds a mathematics competition.

First, second and third prizes. Obtain.

The number of first and second prizes accounts for three-fifths of the total number of winners.

The number of second and third prizes accounts for nine-tenths of the total number of winners. Obtain.

What percentage of the first, second and third prizes are the total number of winners?

The third prize accounted for 1-3 5=2 5

The first prize winner accounts for 1-9 10=1 10

The third prize accounted for 1-2 5-1 10 = 1 2

3.A workshop produces parts, the first half of the month to complete five-ninths of the monthly plan, the second half of the month to complete two-thirds of the monthly plan, the whole month to exceed the monthly plan?

4.In the fifth grade, 30 students participated in the tree planting activity, and one-third of the students dug the pit and one-fifth of the students carried water. The rest of the students are cultivating soil, how many students are cultivating soil?

30*(1-1 3-1 5)=30*7 15=14 people.

5.A children's book has a total of 75 pages, and Xiaoxiao plans to read it in 5 days, how many fractions of the average daily reading of this book? What fraction of a day do you have to read this book in 4 days? How many pages do you read per day on average?

75 5 = 15 pages or 75 * 1 5 = 15 pages.

2.3rd Prize 1-3 5=2 5 2nd Prize 9 10-2 5=1 2 1st Prize 3 5-1 2=1 10

Person.; 4*1/5=4/5;75 5 = 15 pages.

This depends on the type of question.

If it's a problem, you need an answer; If it is a columnar calculation, you do not need to write an answer.

If you have a unit, you should bring the unit. If you answer, you usually write an answer when you solve the problem.

3*5-15=3 so. There are 3 more motorcycles than cars. There are 4 motorcycles and 1 car. 1 tricycle.

There are A motorcycles, B tricycles, and C cars.

a+b+c=6

2a+3b+4c=15

a, b, and c are greater than or equal to 1, respectively

According to the equation, the maximum value of c is 2

Substituting c = 2 yields: 2a + 3b + 8 = 15 a + b + 2 = 6 to calculate a = 2, b = 1 and a + b + c is only equal to 5, so there is no title.

Substituting c 1 into 2a+3b+4=15 a+b+c=6 gives a=4 b=1 c=1

There are motorcycles, tricycles, and cars respectively: X, Y, and Z.

From the question, it can be seen that x+y+z=6 2x+3y+4z=15 x, y, z are all natural numbers.

x=4 y=1 z=1

a+b+c=6, after 2 times, 2a+2b+2c=12

2a+3b+4c=15, subtract these two equations to get 2c+b=3, so c=1, b=1, and find a=4

Solve the system of equations Set x motorcycles, y tricycles, and z cars. The equation is:

2x+3y+4z=15

x+y+z=6

0《x《70《y《5

0《z《3

Sweat. Wrong.

3 rounds of 3 pcs. 2 motorcycles.

4 cars.

Add together greater than 15

How about 15 wheels?

If that's what the book is.

Then there's something wrong with your book.

There was a problem with the question.

You can reflect like the teacher.

Solution: X teaching instruments were damaged in the accident.

From the meaning of the title. 20×15－（15＋80）x＝－175

x 5 A: 5 teaching instruments were damaged in the accident.

Let x be lost: 20*15-x*(15+80)=-175. for five.

1.Xiaohua: 33 (4-1) = 11 (years old) Dad: 11 4 = 44 (years old).

2.It is more appropriate to choose an edge length of 4dm;

Because both meters and meters are integer multiples of 4dm, (32 4) (28 4) = 8 7 = 56 (blocks).

3.There are a total of 8 types of laying methods for laying pipes.

84 = 3 m 28 roots.

84 = 3 m 24 + 4 m 3 84 = 3 m 20 + 4 m 6 84 = 3 m 16 + 4 m 9 84 = 3 m 12 + 4 m 12 84 = 3 m 8 + 4 m 15 84 = 3 m 4 + 4 m 18 84 = 4 m 21.

1.33 (4-1)=11 (years old) 11*4=44 (years old) Answer: Dad is 44 years old this year, and Xiaohua is 11 years old this year.

2.It is appropriate to choose an edge length of 4dm. Because the length and width of the living room are multiples of 4, that is to say, the floor tiles with a side length of 4dm do not need to be cut, and there is no waste.

3.(1) 84 3 = 28 (root).

2) 84 4 = 21 (root).

3) 84 (3+4) = 12 (root).

A: You can use 28 sticks, 12 sticks of 3 meters, 21 sticks of 4 meters, or 12 pieces of 3 meters and 4 meters.

Xiao Ming: 33 3 = 11 (years old) Dad: 11 + 33 = 44 (years old).

Because 32 4 = 8 28 4 = 7, I choose 4dm.

3.84 3=28 83 4=20 ......3m so 20 x 4m and 1 x 3m.

(1) (58-16-11) 2=15·5 (16 willow saplings and 11 poplar saplings are planted, and each type of remaining tree).

The tree of the tree cannot be a decimal, there is no solution to this problem.

2) 116 2-8+12=62 (trees) The number of people in workshop A: 116-62=54 (trees) The number of people in workshop B.

1.There are a total of 58-16-11 = 31 saplings left in the two saplings, and the question is problematic and should be divisible by 2.

2.It turns out that workshop A has 12-8 = 4 more people than workshop B, and workshop B: (116-4) 2=56 people.

Workshop A: 116-56 = 60 people.

The first question has a remainder that cannot be counted.

116 2 58 (name).

58 4 62 (name).

A: It turned out that there were 62 workers in workshop A.

58-4=54 (name).

A: It turned out that there were 54 workers in a workshop.

From 9 a.m. to 12 p.m., 3 hours = 180 minutes!

One-way calculation, a time 9 + 5 = 14 minutes;

180 14=12, remaining 12;

12-9=3, i.e. he was resting on the North Shore at this time and had a 3-minute rest.

Consider setting up a cycle of "South Shore (9 minutes) North Shore (5 minutes) Rest (9 minutes) South Shore (5 minutes) Rest".

As you can tell from the title, each cycle takes time.

9+5+9+5=28 (minutes).

From 12 o'clock to 9 o'clock there is a total of one.

12-9 = 3 (hours) = 180 (minutes).

The number of cycles that can be performed in this 180-minute period is 180 28 = 6 ......12

This means that at 12 o'clock the person is doing the 7th cycle and doing it for 12 minutes.

According to the initial cycle, since 9 12 9 + 5 = 14, at the 12th minute of the 7th cycle, the person is resting on the North Shore.

Every 28 minutes, he returns to his original state.

From 9 a.m. to 12 p.m., it took 3 hours and 300 minutes.

So it took 10 28 minutes plus 20 minutes.

And after the first 20 minutes, he was paddling from the north shore to the south shore.

But there's no way to list this thing.

9-12 o'clock.

When the difference is 3, that is, 3 60 = 180 minutes.

Each cycle takes (9+5) 2=28 minutes.

3-5 = Negative.

That is, he was resting at 12 o'clock.

1.4/5 of a kilometer = 800 meters.

800*60%=480 meters.

3/10 km = 300 m.

480-300 = 180 meters.

2. Half of the total length is 50%, then 30% + 50% = 80% was repaired in the first 2 months, and the remaining 8 kilometers are 20% of the total length

So the total length is: 8 20% = 40 km.

The discount is 10% cheaper, and the difference between the two methods is equivalent to 5% + 10% = 15% = 30,000 yuan of the house price.

The house price is: 3 15% = 200,000.

All hands on... Remember to give points.

1.4 5*60%-3 10=9 50 km (or km).

2.The total length of the road is 8 (1-30%-50%) = 40 km.

3.The price of this commercial house is 3 (1+5%-90%) = 200,000 yuan.

1. Solution: 4 5x60%-3 10=12 25-3 10=24 50-15 50=km.

2. Solution: 8 (1-30%-1 2)=8 (1 5)=40 km.

2. Solution: 3 (1+5%-9 10)=3 (3 20)=200,000 yuan.

1.4 5 kilometers is 800 meters, 3/10 meters is 300 meters, 6/10 of 800 meters is 480 meters, and 300 meters have been dug, then 800 multiplied by 6/10 and subtracted 300 equals 18.

2.Half of the total length has been repaired, and there are still 8 kilometers that have not been repaired, which means that these 8 kilometers are the remaining 20 percent, so the total length of the road is 40 kilometers.