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Course: 8th grade > Unit 1
Lesson 12: Scientific notation word problemsNumbers and operations: FAQ
Frequently asked questions about numbers and operations
What are repeating decimals?
Repeating decimals are when a pattern of numbers repeats over and over after the decimal point. For example, the fraction is equivalent to the decimal , which is a repeating decimal.
The bar over the means that it repeats forever:
What are square roots and cube roots?
Square roots and cube roots are used all the time in math and science. When we want to find the side length of a square with a given area, we use square roots. When we want to find the length of a cube with a given volume, we use cube roots.
What are irrational numbers?
Irrational numbers are numbers that can't be written as a fraction of two integers. For example, is an irrational number, because no matter how hard we try, we can't find two integers that will give us when we divide them.
What does "approximating irrational numbers" mean?
When we approximate an irrational number, we're finding a rational number that is close to the irrational number. For example, we could say that .
What are exponent properties?
Exponent properties are rules that we can use to simplify expressions that contain exponents.
Product rule: . For example, .
Power rule: . For example, .
Quotient rule: . For example, .
Zero exponent rule: . For example, .
What is scientific notation?
Scientific notation is a way of writing really big or really small numbers in a way that makes them easier to work with. For example, is hard to read, but when we put it in scientific notation, we get . This is much easier to read and work with.
Where is scientific notation used in the real world?
Scientific notation is used in many different fields, especially in the sciences. Scientists often work with very large or very small numbers, and using scientific notation makes calculations and comparisons much easier.
For example, in chemistry, scientists use scientific notation to express the mass of atoms and molecules in grams, which usually have values much smaller than .
Another example: we might want to calculate the distance that light travels in one year. We can use scientific notation to express the speed of light as meters per second and multiply that by the number of seconds in a year to get our answer.
Want to join the conversation?
- What is an easy way to remember scientific notation?(12 votes)
- One way to remember it is you multiply ten by the number that you have. Another way is to remember to add the zeros after (or before) the number. That's how I remember it. Hope that helps!(10 votes)
- what's an easy way to remember scientific notation(5 votes)
- Watch the videos.(12 votes)
- "don't let what you khannot do interfere with what you khan do"(7 votes)
- why was the scientific notation word problems so hard?(7 votes)
- I swear no matter how much hints are thrown at me i dont get it(6 votes)
- i tried the questions on a paper and checked it again and i thought i was correct but none of my answers were correct, i know im doing it correct but idk its showing me that do u know what videos to watch when confused in what symbol to use for scientific notations??(3 votes)
- KA user Rachel McDonald, in another post, recommended Tyler DeWitt’s series on YouTube. His explanations of scientific notation are excellent! He approaches the problem from a slightly different angle. I highly recommend it. You can thank Rachel for this one.(7 votes)
- what is an easier way to write the answer to scientific notation? for example- 3.5 times 10^5 = 350000. How could we write 350000 easier? Bc I don't want to write that much.(4 votes)
- 3.5 * 10^5 is the scientific notation for 350000.(3 votes)
- How can I Know if I multiplied the equation right?(4 votes)
- I don't understand scientific notation(3 votes)
- What don't you get hm?(1 vote)
- look at my explanation, hope it helps! :)(3 votes)