Question 7615
with scientific notation, for adding and subtracting, the powers have to be the same: so we need to convert the 5 to a 4 or the 4 to a 5, whichever...


3.2x10^5 is te same as 32x10^4, so we now have: 


2.8x10^4 + 32x10^4 and now we can add the numbers, to give 34.8x10^4.


Re-writing this as "standard form", which means a number from 1 upto (but not equal to) 10, gives the final answer as 3.48x10^5.



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If we had converted the 2.8x10^4 into 0.28x10^5 in the first place and then added, we would have gotten 3.48x10^5 straight away. Oh well :-)


jon.