How do you convert #4.9xx10^-7# to standard form?

2 Answers
Sep 27, 2016

In standard form #4.9xx10^(-7)=0.00000049#

Explanation:

In scientific notation, we write a number so that it has single digit to the left of decimal sign and is multiplied by an integer power of #10#.

In other words, in scientific notation, a number is written as #axx10^n#, where #1<=a<10# and #n# is an integer and #1<=a<10#.

To write the number in normal or standard notation one just needs to multiply by the power #10^n# (or divide if #n# is negative). This means moving decimal #n# digits to right if multiplying by #10^n# and moving decimal #n# digits to left if dividing by #10^n# (i.e. multiplying by #10^(-n)#).

In the given case, as we have the number as #4.9xx10^(-7)#, we need to move decimal digit to the left by seven points. For this, let us write #4.9# as #000000049# and moving decimal point seven points to the left means #0.00000049#

Hence in standard form #4.9xx10^(-7)=0.00000049#

Oct 4, 2016

#4.9xx10^(-7) = 0.00000049#

Explanation:

#4.9xx10^(-7)# is the same as #4.9xx1/(10^7)#

Taking it stepwise so that you can see what is happening:

#4.9xx1/10^7#

#0.49xx1/10^6#

#0.049xx1/10^5#

#0.0049xx1/10^4#

#0.00049xx1/10^3#

#0.000049xx1/10^2#

#0.0000049xx1/10^1#

#0.00000049xx1/10^0#

But #1/10^0 = 1/1 = 1# giving

#0.00000049xx1 " "=" "0.00000049#

So #4.9xx10^(-7) = 0.00000049#