Text and Images Copyright (C) 2006 Mike Sebastian

Sub-Five Dollar Scientific Calculators - LeWORLD 2099

For five dollars, this is actually a pretty decent calculator. It has a decent sized display. The keys are hard plastic, with primary functions printed on the keys. The hinged cover, which snaps in place to protect the keyboard and display, is a nice feature.

This calculator is one of numerous 56-function models on the market, so the function suite is well know. The calculator has the normal arithmatic functions, common and natural logarithms, trigonometric functions in three angular modes, hyperbolic functions, sexigesimal conversions, complex math, polar-rectangular coordinate conversions, binary/octal/hexadecimal support, single variable statistics, and one independent memory. The calculator uses the standard algebraic logic system.

The LeWORLD 2099 in its packaging.

The LeWORLD 2099 scientific calculator. Yes, the constants table sticker came from the factory crooked.

The fold-over cover (left), case back (center), and case front and electronics (right). The PCB is single sided. The three screw posts at the top of the case front were all split.

The PCB unscrewed from the case front. The battery contacts are heat staked to the case front.

A close-up of the PCB. The black lines are conductive ink that has been silkscreened onto the PCB to form the necessary jumpers. Under the black conductors, but above the solder mask, dark green insulators have been printed.