What You'll Learn
- Memorize all doubles from 1+1 through 9+9
- Solve near-doubles by adjusting a known double
- Apply doubling to multiplication preview
Explanation
Doubles form a rhythm: 2, 4, 6, 8, 10, 12, 14, 16, 18. Say them in order daily until the sequence is automatic.
For a near-double like 6 + 7, think of the double 6 + 6 = 12, then add 1 to get 13. The adjustment is always ±1 or ±2.
Doubles connect directly to multiplication: knowing 7 + 7 = 14 means 7 × 2 = 14 is already half-learned.
When both numbers are close, pick the smaller double as your anchor. For 8 + 9, use 8 + 8 = 16, then +1 = 17.
Pro Tips
- • Create a "doubles chart" and cover one side to quiz yourself.
- • Near-doubles always differ by 1 or 2 — identify which before calculating.
- • Doubles of 5 and near-5 facts end in 0 or 5, making them easy to spot.
Practice Exercises
Work through each problem mentally. Click "Show Answer" when you're ready to check.
- 1. 6 + 6 = ?
- 2. 7 + 7 = ?
- 3. 6 + 7 = ?
- 4. 8 + 8 = ?
- 5. 8 + 9 = ?
- 6. 4 + 4 = ?
- 7. 4 + 5 = ?
- 8. 9 + 9 = ?
- 9. 9 + 8 = ?
- 10. 3 + 4 = ?