1-Digit Addition Practice
Practice basic single-digit addition facts, including sums greater than 9, to build speed and confidence with everyday mental math.
What You'll Practice
- ✓ All 81 single-digit addition facts (1+1 through 9+9)
- ✓ Sums greater than 9 (e.g., 7 + 8 = 15) — the hardest and most important facts
- ✓ Instant feedback on every answer with streak tracking
- ✓ Streak tracking and best score saved in your browser automatically
Mental Math Strategies
Count On
Start from the larger number and count up. For 3 + 7: start at 7, count up 3 → 8, 9, 10.
Make Ten
For 8 + 6: split 6 into 2 + 4. Then 8 + 2 = 10, and 10 + 4 = 14.
Use Doubles
Know that 6 + 6 = 12, so 6 + 7 = 13 (one more). Doubles are easy to memorize.
Frequently Asked Questions
What grade is 1-digit addition?
1-digit addition is a core Kindergarten and Grade 1 skill. Students work toward fluency with all 81 single-digit addition facts (1+1 through 9+9) before moving on to two-digit addition.
What does "sums greater than 9" mean in addition?
When two single digits add up to 10 or more (for example, 7 + 8 = 15), the sum is greater than 9. These facts are especially important because they lay the groundwork for understanding carrying in multi-digit addition.
How do I get faster at single-digit addition?
The most effective strategies are: counting on from the larger number (for 3 + 7, start at 7 and count up 3), making 10 (for 8 + 6, split 6 into 2 + 4, then add 8 + 2 = 10, then + 4 = 14), and using doubles (knowing 6 + 6 = 12 helps quickly solve 6 + 7 = 13). Daily short practice sessions build speed faster than occasional long sessions.
How many addition facts are there?
There are 81 single-digit addition facts (1+1 through 9+9). If you include 0 as an addend, there are 100 (0+0 through 9+9). Most curricula focus on the 81 non-zero facts for fluency practice.