← Back to Class 2🔒
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Class 2 · Topic 2
Addition & Subtraction to 20
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Step 1 · Learn
Read the ideas
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Adding Within 20
Hold the big number in your head.
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Doubles & Near-Doubles
The doubles you know unlock the sums next door.
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Make Ten to Add
Ten plus a bit is the easiest sum there is.
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Subtracting Within 20
Taking away is counting on, run backwards.
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Fact Families
The biggest number is always the total.
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Missing Numbers & Adding Three
Subtract to find a gap; add three two at a time.
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Step 2 · Practice
Try the quests
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Step 3 · Boss Battle
Beat the boss
🛡️ 🛡️ 🛡️ 3 shields — lose all → 60-second cooldown
Round 1
Adding Within 20
🔒Round 2
Make Ten to Add
🔒Round 3
Subtracting Within 20
🔒Round 4
Doubles & Near-Doubles
🔒Round 5
Fact Families
🔒Round 6
Missing Numbers & Adding Three
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