Teens’ math skills are getting worse: They’ve been asked these questions | last
Onderaan dit artikel zijn de antwoorden geplaatst. Daar zie je ook hoe moeilijk elke vraag is. Niveau 1 is het makkelijkst en niveau 6 is het moeilijkst. Je mag een rekenmachine gebruiken.
Zonnestelsel
at first an item A table shows the distance between different planets and the Sun. You have to place the planets in the right place based on the distance between each other.
1.1 What are the planets that are 4.38 astronomical units apart? What are the planets located at a distance of 9.63 astronomical units?
1.2 Neptune is 30.05 astronomical units away from the Sun. How many million kilometers is that if one astronomical unit equals 150 million kilometers?
triangle
with this an item A triangle consisting of other triangles appears. Some triangles are blue and some are red.
2.1 Six blue triangles and ten red triangles are shown. What percentage of the triangles are blue?
2.2 Suppose another row is added to the bottom of the form. What percentage of the triangles are blue?
2.3 Does the proportion of blue triangles always remain less than 50 percent, no matter how many rows are added? Why and why not?
Forest area
This section is about forest area amounts for each country. The table shows forest area as a percentage of total land area in fifteen countries. This number is displayed for three moments: 2005, 2010, and 2015.
You need the interactive table to calculate. you can do it here Find.
3.1 Which country saw the largest increase in forest area, in percentage points, between 2005 and 2015? In which country was there no increase between 2005 and 2015? Which country saw the largest decline, in terms of percentage points, between 2005 and 2015?
3.2 What is the average change in forest area between 2005 and 2010? Is this positive or negative? Between 2010 and 2015?
3.4 “South Korea has more forest area in the years shown than any other country on this list.” Is this statement true or not? And why?
Solar system answers
1.1 (Difficulty level: 3) The correct answer is: Jupiter, Saturn, and Uranus.
The distance between the planets is determined by comparing the distance between the planets and the Sun. The distance from Saturn to the Sun minus the distance from Jupiter to the Sun is 4.38 astronomical units (Saturn – Jupiter = 4.38 astronomical units). The distance from Uranus to the Sun minus the distance from Jupiter to the Sun is 9.62 astronomical units (Uranus – Saturn = 9.62 astronomical units).
1.2 (Difficulty level: 2) The correct answer is: 4,500 million kilometers.
Neptune is 30.05 astronomical units away from the sun. 30.05 times 150 million equals approximately 4,500 million kilometers (30.05 x 150,000,000 = 4,507,500,000).
Answers in a triangular pattern
2.1 (Difficulty level 1): The correct answer is 37.5 percent. On paper, this is the easiest question on the test.
There are 6 blue triangles and 10 red triangles. Total of 16 triangles (6 + 10 = 16). The percentage of blue triangles is calculated by dividing 6 by 16 and then multiplying by 100 (6 / 16 x 100 = 37.5).
2.2 (Difficulty level 2): The correct answer is 40 percent.
When you add another row, there will be 5 red rows and 4 blue rows Triangles bee. So there are 25 triangles in total. The percentage of blue triangles is calculated by dividing 10 by 25 and then multiplying by 100 (10 / 25 x 100 = 40).
2.3 (Difficulty level 5): The correct answer is “Yes”.
Explanation: There is always one more red triangle in each row than the blue triangle. At 50 percent, the number of blue triangles will be equal to the number of red triangles. This is not possible if there are always more red triangles in each row.
Wooded area answers
3.1 (Difficulty level 5): The correct answers to the questions are: Greece has the largest increase, Armenia has no increase, and Panama has the largest decrease.
Explanation: You calculate the difference by subtracting the situation in 2005 from the situation in 2015. So column D minus column B (D – B = difference). You can then sort by column E. The higher the number, the greater the difference between the two moments. A negative number means that there are fewer forests in 2015 than in 2005.
In Greece, the difference is 2.34 percentage points, and this is the largest difference. In Armenia, the difference is 0.00 percentage points, so there is no change between 2005 and 2015. In Panama, the decline was larger at -2.22 percentage points.
3.2 (Difficulty level 5): The correct answer is that the difference between them is negative on average.
You calculate the difference for the first time difference by subtracting the position in 2005 from the position in 2010, i.e. column C minus column B (c – b = difference). You can then also do this for the second time difference, i.e. 2015 minus 2010, or column D minus column C (D – C = difference).
You can then determine the average for columns E and F. In column E, the difference between 2005 and 2010, the number is -0.15 and so the percentage of forest area is decreasing. In column F, the difference between 2010 and 2015 is -0.13 and the percentage of forest area is also decreasing.
3.4 (Difficulty level 6): The correct answer is “No”.
Forest area is given in percentages. South Korea has the largest percentage (64.42). This means that more than half of South Korea’s area is covered by forests. But more than half the area of South Korea is not necessarily larger than a third of the area of the United States (33.85%), for example. So you need the surface area of each country.
Without knowing how much land each country has, you cannot determine which country has the largest area of forest.
Is your due date not yet? On the website From the OECD you can find more arithmetic questions.
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