Engineering Notation - Casio fx-991EX Quick Start Manual

To find the difference between one US Gallon and one UK
Gallon, first, convert to a common unit, like a liter (L).
Press 1q8(CONV)3(Volume)
1(gal(US) : L)p.
One US gallon is approximately 3.785 L.
Now, convert the solution to gallons UK.
Press q8(CONV)3(Volume)4
(L : gal(UK))p.
It looks like a US gallon is smaller.
1 US gallon = 0.8326742321 UK gallons.
The same calculation can be accomplished using a
string of conversions.
Press 1q8(CONV)3(Volume)
1(gal(US) : L)q8(CONV)
3(Volume)4(L: gal(UK))p.

ENGINEERING NOTATION

Converting large numbers into scientific and engineering notations
can be accomplished through a short series of keystrokes.
Start with a large number like 2.5 X 10
Press 2.5K9p.
The gap between digits at place value separation can be viewed
by entering Set Up. Press qp(SET UP) and use the arrow
keys to navigate to the third menu.
8
.
9
CALCULATE
fx-991EX Quick Start Guide