[The units of linear measure most commonly used are millimeters (mm.), centimeters (cm.),
decimeters (dm.), meters (m.), and kilometers (km.), 1 m. = 10 dm.; 1 dm. = 10 cm.;
1 cm. = 10 mm.; 1 km. = 1,000 meters = 0.62137 mile; 1 m. = 39.37 inches = 3.280833 feet.]
| Meters. | Inches. | Meters. | Feet. | Kilometers. | Miles. |
| 1 | 39.37 | 1 | 3.280633 | 1 | 0.62137 |
| 2 | 78.74 | 2 | 6.561667 | 2 | 1.24274 |
| 3 | 118.11 | 3 | 9.842500 | 3 | 1.86411 |
| 4 | 157.48 | 4 | 13.123333 | 4 | 2.48548 |
| 5 | 196.85 | 5 | 16.404166 | 5 | 3.10685 |
| 6 | 236.22 | 6 | 19.685000 | 6 | 3.72822 |
| 7 | 275.59 | 7 | 22.965833 | 7 | 4.34959 |
| 8 | 314.96 | 8 | 26.246666 | 8 | 4.97096 |
| 9 | 354.33 | 9 | 29.527500 | 9 | 5.59233 |
| Inches. | Centimeters. | Feet. | Meters. | Miles. | Kilometers. |
| 1 | 2.54 | 1 | 0.304801 | 1 | 1.60935 |
| 2 | 5.08 | 2 | 0.609601 | 2 | 3.21869 |
| 3 | 7.62 | 3 | 0.914402 | 3 | 4.82804 |
| 4 | 10.16 | 4 | 1.219202 | 4 | 6.43739 |
| 5 | 12.70 | 5 | 1.524003 | 5 | 8.04674 |
| 6 | 15.24 | 6 | 1.828804 | 6 | 9.65606 |
| 7 | 17.78 | 7 | 2.133604 | 7 | 11.26543 |
| 8 | 20.32 | 8 | 2.438405 | 8 | 12.87478 |
| 9 | 22.86 | 9 | 2.743205 | 9 | 14.48412 |
The "vara," used in Texas, is equivalent to 331/3 inches and is computed as representing 2.78 feet.
Geologic eras, periods, systems, epochs, and series.
| Era. | Period or system. | Epoch or series. | ||
| Cenozoic. |  | Quaternary. |  | Recent. Pleistocene (replaces "Glacial"). |
| Tertiary. |  | Pliocene. Miocene. Oligocene. Eocene. | ||
| Mesozoic. |  | Cretaceous. | | Upper (Gulf may be used provincially). Lower (Comanche and Shasta may be used provincially). |
| Jurassic. | | Upper. Middle. Lower. | ||
| Triassic. | | Upper. Middle. Lower. | ||
| Paleozoic. |  | Carboniferous. | | Permian. Pennsylvanian (replaces "Upper Carboniferous"). Mississippian (replaces "Lower Carboniferous"). |
| Devonian. | | Upper. Middle. Lower. | ||
| Silurian. | ||||
| Ordovician. | | Upper (Cincinnatian may be used provincially). Middle (Mohawkian may be used provincially). Lower. | ||
| Cambrian. | | Saratogan (or Upper Cambrian). Acadian (or Middle Cambrian). Waucoban (or Lower Cambrian). | ||
| Proterozoic. | | Algonkian. Archean. |  | pre-Cambrian. |
Chemical elements and symbols.
| Element. | Symbol. | Element. | Symbol. | Element. | Symbol. | ||
| Aluminum | Al | Holmium | Ho | Rhodium | Rh | ||
| Antimony | Sb | Hydrogen | H | Rubidium | Rb | ||
| Argon | Al | Indium | In | Ruthenium | Ru | ||
| Arsenic | As | Iodine | I | Samarium | Sa | ||
| Barium | Ba | Iridium | Ir | Scandium | Sc | ||
| Bismuth | Bi | Iron | Fe | Selenium | Se | ||
| Boron | B | Krypton | Kr | Silicon | Si | ||
| Bromine | Br | Lanthanum | La | Silver | Ag | ||
| Cadmium | Cd | Lead | Pb | Sodium | Na | ||
| Cesium | Cs | Lithium | Li | Strontium | Sr | ||
| Calcium | Ca | Lutecium | Lu | Sulphur | S | ||
| Carbon | C | Magnesium | Mg | Tantalum | Ta | ||
| Cerium | Ce | Manganese | Mn | Tellurium | Te | ||
| Chlorine | Cl | Mercury | Hg | Terbium | Tb | ||
| Chromium | Cr | Molybdenum | Mo | Thallium | Tl | ||
| Cobalt | Co | Neodymium | Nd | Thorium | Th | ||
| Columbium | C | Neon | Ne | Thulium | Tm | ||
| Copper | Cu | Nickel | Ni | Tin | Sn | ||
| Dysprosium | Dy | Niton | Nt | Titanium | Ti | ||
| Erbium | Er | Nitrogen | N | Tungsten | W | ||
| Europium | Eu | Osmium | Os | Uranium | U | ||
| Fluorine | F | Oxygen | O | Vanadium | V | ||
| Gadolinium | Gd | Palladium | Pd | Xenon | Xe | ||
| Gallium | Ga | Phosphorus | P | Ytterbium | |||
| Germanium | Ge | Platinum | Pt | (Neoytterbium) | Yb | ||
| Glucinum | Gl | Potassium | K | Yttrium | Y | ||
| Gold | Au | Praseodymium | Pr | Zinc | Zn | ||
| Helium | He | Radium | Ra | Zirconium | Zr |
Greek alphabet.
| Caps. | Lower-case. | Greek name. | English sound. | Caps. | Lower-case. | Greek name. | English sound. | |
| Α | α | Alpha. | A. | Ν | ν | Nu. | N. | |
| Β | β | Beta. | B. | Ξ | ξ | Xi. | X. | |
| Γ | γ | Gamma. | G. | Ο | ο | Omicron. | O short. | |
| Δ | δ | Delta. | D. | Π | π | Pi. | P. | |
| Ε | ε | Epsilon. | E short. | Ρ | ρ | Rho. | R. | |
| Ζ | ζ | Zeta. | Z. | Σ | σ | Sigma. | S. | |
| Η | η | Eta. | E long. | Τ | τ | Tau. | T. | |
| Θ | θ | Theta. | Th. | Υ | υ | Upsilon. | U. | |
| Ι | ι | Iota. | I. | Φ | φ | Phi. | F. | |
| Κ | κ | Kappa. | K. | Χ | χ | Chi. | Ch. | |
| Λ | λ | Lambda. | L. | Ψ | ψ | Psi. | Ps. | |
| Μ | μ | Mu. | M. | Ω | ω | Omega. | O long. |