University of Illinois
University of Illinois: Mste: Flash Card Applet
In this activity, students solve addition or subtraction of one- and two-digit numbers as their progress is checked.
CK-12 Foundation
Ck 12: Elem Math: Filling in the Missing or Sign Numbers to 1000
[Free Registration/Login may be required to access all resource tools.] The video works through a 3-digit addition problem to determine if the correct operation for the number sentence is addition or subtraction. The video is followed by...