Number Bonds to 20 (Grade 1)
Number bonds to 20 build the bridge from single-digit addition to place value fluency. By decomposing teen numbers into a full ten and remaining ones (e.g., 14 is 10 and 4), students transition away from counting on fingers to rapid mental algebraic reasoning.
🧠 Core Mental Strategies & Shortcuts
🔟 The 'Ten Plus Ones' Teen Anchor
Every teen number (11–19) decomposes naturally into a group of 10 plus extra ones. For 16, the anchor bond is 10 and 6!
🌉 The Bridge to 10 Strategy
When adding non-10 parts like 8 + 7, split 7 into 2 and 5. Combine 8 + 2 to make 10, then add 5 to reach 15!
👑 Crown the Whole (The Ceiling Rule)
The root circle with two connected branches is always the whole. A part can never be larger than the whole!
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