The sequence of keystrokes directs the calculator to compute
[tex]\dfrac{5\cdot 10^{-9}}{2\cdot 10^4}=\dfrac{5}{2}\cdot 10^{(-9-4)}=2.5\cdot 10^{-13}[/tex]
The display will read ...
... A) 2.5E-13
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You can enter these keystrokes on your calculator and get the answer immediately.
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Actually, it is very likely Samuel's calculator displayed 2E4, since the key for "=" has not been pressed.
