Addition Practice (3 Numbers up to 20)
Accuracy: 100%
Streak: 0
Adding 3 Numbers up to 20
Add three numbers where each can be up to 20 (like 15 + 8 + 12).
Student Tips:
- Break larger numbers into 10s and 1s: 15 + 8 + 12 = (10 + 5) + 8 + (10 + 2)
- Add the 10s first: 10 + 10 = 20, then add the 1s: 5 + 8 + 2 = 15, so 20 + 15 = 35
- Look for friendly combinations: 15 + 8 + 12, maybe 8 + 12 = 20, then 20 + 15 = 35
- Use rounding: 15 + 8 + 12 is about 15 + 10 + 10 = 35
Teaching Instruction: Use base-10 blocks to show tens and ones separation. Practice mental math strategies like rounding and adjusting. Show place value organization. Start with numbers that have obvious 10-combinations.
