Addition and Subtraction in Scientific Notation
A number written in scientific notation is written as the product of a number between 1 and 10 and a number that is a power of 10. That is, it is written as a quantity whose coefficient is between 1 and 10 and whose base is 10.
Addition and Subtraction
One of the properties of quantities with exponents is that numbers with exponents can be added and subtracted only when they have the same base and exponent. Since all numbers in scientific notation have the same base (10), we need only worry about the exponents. To be added or subtracted, two numbers in scientific notation must be manipulated so that their bases have the same exponent--this will ensure that corresponding digits in their coefficients have the same place value.
Multiplying a number by another number with the same base is equivalent to multiplying their coefficients and adding their exponents. Therefore, if we want to add two quantities written in scientific notation whose exponents do not match, we can simply write one of the powers of 10 as the product of two smaller powers of 10 , one of which agrees with the other term.
Alternately, if we want to preserve the exponent of the term with the larger power of 10 , we can simultaneously multiply and divide the other term by a power of 10 , applying the rule for multiplication of exponents in one case and dividing the coefficient in the other. It is this procedure that we outline below. Once the numbers have the same base and exponents, we can add or subtract their coefficients.
Here are the steps to adding or subtracting numbers in scientific notation :
1. Determine the number by which to increase the smaller exponent by so it is equal to the larger exponent.
2. Increase the smaller exponent by this number and move the decimal point of the number with the smaller exponent to the left the same number of places. (i.e. divide by the appropriate power of 10 .)
3. Add or subtract the new coefficients.
4. If the answer is not in scientific notation (i.e. if the coefficient is not between 1 and 10) convert it to scientific notation.
Multiplication and Division in Scientific Notation Multiplication and Division
Quantities with exponents can be multiplied and divided easily if they have the same base. Since all number in scientific notation have base 10 , we can always multiply them and divide them.
To multiply two numbers in scientific notation, multiply their coefficients and add their exponents. To divide two numbers in scientific notation, divide their coefficients and subtract their exponents. In either case, the answer must be converted to scientific notation.
Here are the steps to multiply two numbers in scientific notation:
1. Multiply the coefficients--round to the number of significant figures in the coefficient with the smallest number of significant figures.
2. Add the exponents.
3. Convert the result to scientific notation.
Here are the steps to divide two numbers in scientific notation:
1. Divide the coefficients--round to the number of significant figures in the coefficient with the smallest number of significant figures.
2. Subtract the exponents.
3. Convert the result to scientific notation.
yes its really important
2,430,000 in scientific notation is 2.43 × 106
The scientific notation of 4.2ns is 4.2 × 100ns
200.1 in scientific notation is: 2.001 × 102
13,500 in scientific notation is 1.35 × 104
Yes, it does.
Ask yourself. Would you rather write this out in long hand? 234,000,000,000,000,000,000 ----------------------------------- Or this? 2.34 X 1020 -------------- Let alone adding, subtracting, multiplying and dividing the first long number.
1 With addition change the scientific notation back to 'normal numbers' and then add accordingly 2 With subtraction change the scientific back to 'normal numbers' and then subtract accordingly 3 With division subtract the exponents and divide the decimals 4 With multiplication add the exponents and multiply the decimals 5 Note that if changes occur below 1 or greater than 9 in the decimal element of the scientific notation then appropriate adjustments must be made
If you are adding or subtracting two numbers in scientific notation, you must rewrite one of the numbers to the same power of ten as the other, before performing the addition (or subtraction).
Add them
yes its really important
You subtract the exponent of the denominator from that of the numerator.
Same.
When adding or subtracting numbers in scientific notation, ensure that the exponents are the same. If the exponents are not the same, adjust one or both numbers to match. Then, add or subtract the coefficients while keeping the exponent the same. Finally, simplify the result if necessary by converting it back to proper scientific notation.
Subtract them.
Multiplying numbers in scientific notation is easier when the numbers are very, very large or very, very small. Multiplying 0.000000000385 x 0.0000000474 is a pain. Multiplying 3.85 x 10-10 x 4.74 x 10-8 is not.
Multiplying each factor by powers of ten