you take the last digit in the first one and add/subtract it to the last digit in the second one and that is your answer
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).
Same.
This is effectively the same as lining up the decimal points when adding or subtracting ordinary decimal fractions.
When adding or subtracting numbers in scientific notation, the exponents must be the same to ensure that the terms are expressed in the same scale. Scientific notation represents numbers as a product of a coefficient and a power of ten, so if the exponents differ, the values are on different scales, making direct addition or subtraction impossible. By adjusting the numbers to have the same exponent, you can accurately combine the coefficients before simplifying the result back into proper scientific notation.
If you are adding or subtracting two numbers in scientific notation the exponents must be the same before adding the coefficients. This is similar to 'like terms' in algebraic expressions. You can't add 5x3 and 3x2 because the exponents are not the same.
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).
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.
This is effectively the same as lining up the decimal points when adding or subtracting ordinary decimal fractions.
Yes, it does.
same number of significant digits
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).
If you are adding or subtracting two numbers in scientific notation the exponents must be the same before adding the coefficients. This is similar to 'like terms' in algebraic expressions. You can't add 5x3 and 3x2 because the exponents are not the same.
When adding or subtracting measurements, the number of significant figures in the result should match the measurement with the least number of decimal places.
It makes calculations with very large and small numbers easier by allowing the 10-factors to be multiplied or divided by adding or subtracting their indices. (The principle of logarithms.)
When adding and/or subtracting, your answer can only show as many decimal places as the measurement having the fewest number in the decimal places.
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.