Add two 3-digit multiples of 10 (timed)
Add two 3-digit multiples of 10 not crossing the tens or hundreds boundaries.
Add two 3-digit multiples of 10 (timed)
Add two 3-digit multiples of 10 not crossing the tens or hundreds boundaries.
Add two 3-digit multiples of 10 not crossing the tens or hundreds boundaries.
Add two 3-digit multiples of 10 not crossing the tens or hundreds boundaries.