Question 1139879
2.8 billion is {{{ 2.8*10^9 }}}
28.5 million is {{{ 2.85*10^7 }}}
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{{{ 2.8*10^9 - 2.85*10^7 }}}
{{{ 2.8*10^9 - .0285*10^9 }}}
{{{ ( 2.8 - .0285 )*10^9 }}}
{{{ 2.7715*10^9 }}} mi
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Note that when you have {{{ a*10^b }}}
if you increase {{{ b }}}. then you must 
move the decimal point of {{{ a }}} the same
number of places
to the left so you make {{{ a }}} 
smaller