Activity: Encode and decode messages to determine the form for an affine cipher. Input a message to encode, then input your guesses for the constant and multiplier. Caesar Cipher II is one of the Interactivate assessment explorers.

Activity: Decode encrypted messages to determine the form for an affine cipher, and practice your reasoning and arithmetic skills. Input your guesses for the multiplier and constant. Caesar Cipher III is one of the Interactivate assessment explorers.

Activity: Visualize factors through building rectangular areas on a grid. As you draw each factor set on the grid, the factors will be listed. Factorize 2 is one of the Interactivate assessment explorers.