Decode the secret message Ninja Aki has sent you! He writes his messages in addition and subtraction problems. Solve and unravel his secret ninja message!

Subtract the numbers to find the difference, then color code the answer for odd or even.

Secret codes and ninjas make everything more interesting, including subtracting 4-digit numbers!

See subtraction success with a fun practice sheet! Beginners will review basic subtraction facts as they unlock a hidden fun fact at the bottom of the page.

What kind of music do stones listen to? Solve these four-digit subtraction problems to find out.