Addition Fundamentals — copy Addition Fundamentals copy 1) Add Tens by One-Digit 1) Add Tens by One-Digit START 2) Add Two-Digit number by 10 2) Add Two-Digit number by 10 START 3) Add Three-Digit number by 10 3) Add Three-Digit number by 10 START 4) Add Three-Digit number by 100 4) Add Three-Digit number by 100 START 5) Basic Addition 5) Basic Addition START 6) Determine Unknown Number in Addition Equation 6) Determine Unknown Number in Addition Equation START 7) Add Two-Digit number by One-Digit 7) Add Two-Digit number by One-Digit START 8) Add Hundreds by One-Digit 8) Add Hundreds by One-Digit START 9) Add Two-Digit number by multiple of ten 9) Add Two-Digit number by multiple of ten START 10) Add Two-Digit number by Two-Digits 10) Add Two-Digit number by Two-Digits START 11) Add Three-Digit number by One-Digit 11) Add Three-Digit number by One-Digit START 12) Add Three-Digit number by multiple of one hundred 12) Add Three-Digit number by multiple of one hundred START 13) Add Three-Digit number by multiple of ten 13) Add Three-Digit number by multiple of ten START 14) Add Three-Digit number by Two-Digits 14) Add Three-Digit number by Two-Digits START 15) Add Three-Digit number by Three-Digits 15) Add Three-Digit number by Three-Digits START