How to use scientific constants on your calculator
Sumi has 40 scientific constants built in, from the speed of light to standard gravity. Insert one from the ••• menu and use it like any other number.
Insert a constant
- Tap •••, then Constants.
- Type the constant’s two-digit number, such as 2 8 for the speed of light, or tap it in the list.
- Tap =. The answer is 299 792 458, in metres per second.
Use constants in a calculation
A constant works anywhere a number does. ••• Constants 3 5 × 2 = gives 19.6133: twice standard gravity, 9.80665 m/s².
These constants are exact by definition:
- 28 · speed of light in a vacuum, c₀: 299 792 458 m/s
- 35 · standard acceleration of gravity, g: 9.80665 m/s²
- 38 · Celsius temperature, t: 273.15 K
- 40 · standard atmosphere, atm: 101 325 Pa
More constants you might use
The list also includes the Planck constant (06), elementary charge (23), Avogadro constant (24), Boltzmann constant (25), molar gas constant (27) and Newtonian constant of gravitation (39), along with particle masses, magnetons and more. Each has its symbol and unit in the list.
Sumi’s measured constants use the CODATA 2006 recommended values. Since the 2019 SI redefinition, the Planck constant, elementary charge, Avogadro constant and Boltzmann constant are exact, and so is the molar gas constant that follows from them. Their exact values differ from Sumi’s in the sixth to eighth significant figure, so for work that needs current values, check them against a current reference.
To convert between units rather than insert a constant, see how to convert units.
