Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Welcome class! Today, we are diving into the fascinating world of exponents. Can anyone tell me what an exponent is?
Isn't it just the small number that shows how many times the big number is multiplied by itself?
Exactly! We write it as 𝑎^𝑛, where 𝑎 is the base and 𝑛 is the exponent. For example, 2^4 means 2 multiplied by itself 4 times.
So, 2^4 equals 16 then?
Correct! Remember, exponents make it easier to express big numbers, and they have specific laws that help us manipulate them. Let's learn about those rules.
Now that we understand what exponents are, let’s look at the Laws of Exponents. Can anyone name one?
How about the Product of Powers Law?
Exactly! The Product of Powers Law states that when you multiply two powers with the same base, you add their exponents: 𝑎^𝑚 × 𝑎^𝑛 = 𝑎^{𝑚+n}. Let’s practice with an example: what is 3^2 × 3^4?
That would be 3^{2+4} = 3^6, which equals 729!
Great job! Next, we have the Quotient of Powers Law, where we subtract the exponents. Can someone give me that formula?
It's 𝑎^𝑚 / 𝑎^𝑛 = 𝑎^{𝑚-n}!
Correct! Now let’s go through the Power of a Power Law next…
Let’s shift our focus to scientific notation. Who can tell me what scientific notation is?
Is it a way to write really large or small numbers using exponents?
Precisely! Scientific notation is expressed as 𝑁 = 𝑎 × 10^𝑛, where 1 ≤ 𝑎 < 10. For example, 300,000 can be written as 3 × 10^5.
And what about very small numbers like 0.00042?
Great question! That would be written as 4.2 × 10^{-4}. Remember, when you're converting to scientific notation, shift the decimal point and adjust the exponent accordingly.
So we use exponents to make our numbers easier to handle, especially in science?
Exactly right! Scientific notation helps simplify calculations and improves readability of vast data sets.
When multiplying powers with the same base, add the exponents, it’s a simple case.
Once upon a time, a number named 'Two' decided to grow. Whenever he multiplied with himself, he would raise his power, making him 'Four', 'Eight', and more! It was magic, numbers transformed through the power of exponents.
Remember PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. Exponents always come right after parentheses.
RECAP - Remember Exponents Can Add Powers, which summarizes the main law!
Term
What is an exponent?
Click to flip
Term
What happens when you have a negative exponent?
Click to flip
A number indicating how many times a base is multiplied by itself.
The number being multiplied in an exponent expression.
States that when multiplying powers with the same base, add the exponents.
States that when dividing powers with the same base, subtract the exponent of the denominator from that of the numerator.
A method of expressing very large or small numbers using powers of ten.
This section introduces exponents, their laws, and their application in scientific notation.
Exponents, or powers, are critical in algebra for representing and manipulating numbers. This section covers the laws that govern exponents and explores scientific notation, which allows for the expression of large and small numbers efficiently.
Exponents are essential in algebra, where they serve to compactly express the multiplication of a base number by itself a certain number of times. This section defines exponents and outlines the laws that govern their operation, including the Product of Powers, Quotient of Powers, Power of a Power, Power of a Product, Power of a Quotient, Zero Exponent, and Negative Exponent Laws. Each law provides rules for adding, subtracting, or manipulating the exponents when performing calculations. The section also introduces scientific notation, a method for expressing very large or small numbers using exponents. This format is both efficient and effective in various scientific contexts, facilitating easier calculations and comparisons.