Subtract from numbers up to 20 (timed)
Subtract a single digit from a 2-digit number up to 20.
Subtract from numbers up to 20 (timed)
Subtract a single digit from a 2-digit number up to 20.
Subtract a single digit from a 2-digit number up to 20.
Subtract a single digit from a 2-digit number up to 20.