Abstract: A handheld computing device (40) comprises a software application adapted to provide instructions to graphically display a vector on a display screen (48) simultaneously along with the numerical values for components of the vector. The software application may be further adapted to provide instructions to perform a vector math operation on one or more vectors, to allow a user to pick the vector for use in the vector math operation, concurrently while graphically viewing the vector on the display screen (48) simultaneously with its numerical values for components, and/or to allow a user to graphically input the vector by incrementing a vector component with an arrow key (101-104) on the input device (50), concurrently while graphically viewing the vector and vector changes on the display screen (48).

Abstract: A computing device (40) comprises an electrical circuit and a software application. A display screen (138) and an input device (140) are electrically coupled to the electrical circuit. The software application provides instructions to determine the number of significant figures for a number entered via the input device, and simultaneously display on the display screen the entered number along with the number of significant figures for the entered number, and/or the software application provides instructions to calculate a floating point answer for a mathematical operation entered for one or more numbers entered into the computing device, round the floating point answer to the proper precision or to the proper number of significant figures, determine the number of significant figures for the rounded answer, and simultaneously display on the display the rounded answer and its number of significant figures.

Abstract: An improved user interface for a handheld computing device to help a student to easily enter, plot and analyze data such as that on a list. The invention introduces a “wizard” approach user interface that smoothly guides the user through a sequential process of: entering data in one or more lists, viewing the data graphically using one of several common plots, viewing one or more regression functions to fit the data, and analyzing the data using common statistical measures. The user interface brings together some sophisticated graphing tools into a common tool with a simple interface. Thus the present invention allows a user to perform basic list functions with these sophisticated tools with a minimum of experience. An embodiment of the present invention is an application program on a graphing calculator or other computer, which allows the user to display and modify a two dimensional grid of real-time data.

Abstract: A handheld computing device (40) comprises a software application adapted to provide instructions to graphically display a vector on a display screen (48) simultaneously along with the numerical values for components of the vector. The software application may be further adapted to provide instructions to perform a vector math operation on one or more vectors, to allow a user to pick the vector for use in the vector math operation, concurrently while graphically viewing the vector on the display screen (48) simultaneously with its numerical values for components, and/or to allow a user to graphically input the vector by incrementing a vector component with an arrow key (101-104) on the input device (50), concurrently while graphically viewing the vector and vector changes on the display screen (48).

Abstract: A computing device (40) comprises an electrical circuit and a software application. A display screen (138) and an input device (140) are electrically coupled to the electrical circuit. The software application provides instructions to determine the number of significant figures for a number entered via the input device, and simultaneously display on the display screen the entered number along with the number of significant figures for the entered number, and/or the software application provides instructions to calculate a floating point answer for a mathematical operation entered for one or more numbers entered into the computing device, round the floating point answer to the proper precision or to the proper number of significant figures, determine the number of significant figures for the rounded answer, and simultaneously display on the display the rounded answer and its number of significant figures.

Abstract: A ladder comprises a pair of spaced stiles, each having a channel shaped cross-section with the flanges of each stile directed towards those of the other, and a plurality of rungs interconnecting the stiles, each rung also being of general channel section, the tread portion of the rung defining an acute angle with one flange and an obtuse angle with the other flange, and weld beads joining the outer surface of the acute angled rung with one flange of each stile and the inner surface of the obtuse angle rung with the web of each stile.

Abstract: A ladder comprises a ladder portion having stiles and rungs, a platform at the upper end of the ladder portion, support stays hinged to the rear end of the platform, and a safety rail also hinged to the rear end of the platform, and that invention is characterized in that the safety rail can occupy one of two positions, and when in its retracted position it projects forwardly of the platform thereby inhibiting use of the platform.