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Last time, we learned about dividing monomials. Let’s take a short review.
You are given a quotient of monomials.
Select the correct simplified expression from the list. Then, click the “Submit” button.
Now, let’s continue with today’s lesson.
Here we have two large numbers: 2,000,000 and 150,000.
Suppose we wish to multiply them.
The operation is rather cumbersome. We could easily lose track of the place value in the final answer.
Let’s look at the first number. Suppose we rewrite it as the product of two numbers: <EQUATION>
We can rewrite the second term as a power of ten. It becomes <EQUATION>
Likewise, we can transform our second number into <EQUATION>
Now, multiplying the two numbers is easier. We use the product of powers rule to multiply the powers of ten.
The answer is a number times a power of ten: <EQUATION>
We call an expression in this form scientific notation.
The general form is: <EQUATION>. A number in scientific notation is a monomial because it is the product of two numbers.
Let’s convert the number 19200 to scientific notation.
First, we move the decimal place so that only one digit is to the left.
The resulting number, 1.9200, is the first term in the scientific notation expression.
Next, we count the number of places that we moved the decimal place.
In this case, we moved it four places to the left.
What shall we have as the exponent of ten? Click the “Submit” button after entering your answer.
We moved the decimal four places to the left. Therefore, we use four as the exponent of ten.
We can drop the trailing zeroes. The result is the number in scientific notation: <EQUATION>
Here we have a number that is less than one: 0.000023. Let’s convert it to scientific notation.
In this case, we move the decimal five places to the right.
What shall we have as the exponent of ten? Click the “Submit” button after entering your answer.
If we move the decimal to the right, then we set the value as negative.
This gives us the number in scientific notation: <EQUATION>
Now, you try converting some numbers.
You are given a number to convert.
Enter the values for the terms in scientific notation. Then click the “Submit” button.
Remember, if we move the decimal to the left, then the exponent will be positive.
This will be the case when converting numbers greater than one.
If we move it to the right, then the exponent of ten will be negative.
This will be the case when converting numbers less than one.
If we convert the number 1 to scientific notation, the exponent is zero. This is written as <EQUATION>.
Copyright 2006 The Regents of the University of California and Monterey Institute for Technology and Education