Terrific Triangles

Terrific Triangles

Fact Family Flash Cards for Individuals and Groups


A math facts drill-and-practice program that teaches fact families for both addition/subtraction and multiplication/division.


What it does
There are 2 playing modes. In all cases the triangle presents two parts of a fact family and the player must determine the missing third part. The sum and product always appear at the top of the triangle. The addends and factors always go in the two lower corners.


Student mode allows individual facts practice with a running score for correct answers. The player may select difficulty and whether to play against a timer.


Teacher mode allows for group play. Students are presented with a problem and the timer spins one revolution. Then a student name appears and the timer spins again. The student who's name is shown tries to call out the answer before the timer finishes. We like this system of showing the student name after the first spin because, if the time is set short enough, students are encouraged to pay attention even before knowing whether they will need to answer. If they wait until they see their name (or a neighbor tells them to look!) it may be too late to calculate.


How to use it
Press the "Return" or "Enter" key for a new problem to display. The empty corner will be random. If you wish to select which corner will be blank, click that corner with the mouse instead of using the keyboard. Student mode may be used right away. ( Try having students play until they reach a predetermined score. ) Generally teacher mode requires that names be entered first. The names and settings will remain saved between uses.


In the preferences window (see the Edit menu), student names can be typed or pasted. (We recommend using just first names as they are displayed in a large font size and the presentation area is relatively small.) The length of time for one clock revolution can be set and a difficulty level may be selected. The graphics are large enough to be readable on most presentation systems including televisions.


System requirements

Macintosh:  OSX 10.3.9 or greater

Windows:_ 98 or greater. 640 x 480 or greater screen resolution.


Written by Scott Morrow for use in his third grade classroom as a supplement to the Everyday Mathematics program ( SRA / McGraw-Hill. )

Version 1.5.2 Universal Binary build adds native support for Intel based Macs. The preferences file created by this version is incompatible with earlier preference files. In order to revert to a previous (non-UB) version, the preference file must be deleted.

Version 1.5.2: Assorted bug fixes. User-selected ranges of multiplication facts are now followed accurately. Minor appearance enhancements. - June 2006

Version 1.3: Fixes a problem showing student names in "Teacher" mode during multiplication games with a screen resolution larger than 640x480. - March 2006

Version 1.2: General speed increase, native "look and feel" under Windows XP, Windows version now supports copy & paste, fixed problem where timer might freeze during extended teacher-mode use.

Legacy Macintosh:    PPC - OS 9 .sit       68k version

First public release December 2003 - version 1.0.2