## Interactive Multiplication

Try out this interactive applet to visualize, explore, and practice multiplication.

Try out this interactive applet to visualize, explore, and practice multiplication.

When did you learn that there are still unsolved problems in mathematics?

Do you have a favorite unsolved problem?

For me, it’s a close tie among…

The goal of Yodoku is to place consecutive integers 1, 2, 3, … so that the numbers in each row and the numbers in each column are always increasing. This means…