📊 Number Sentences and Bar Models

What you’ll learn

1. Writing a Number SentenceRead and write number sentences using +, −, and =, and know that both sides balance.A number sentence writes math in a line, like 3 + 2 = 5. The + sign means put together, − means take away, and = means 'is the same as.' A word story such as '4 ducks, 1 swims away' becomes 4 − 1 = 3. The = works like a see-saw: both sides must weigh the same.
2. Meet the Bar ModelUse a bar model to split a whole into parts and find a missing part.A bar model is a rectangle that stands for the whole number, split into parts. A bar of 10 can be a part of 6 and a part of 4. If you know the whole is 10 and one part is 7, the empty space shows the missing part is 3. The parts always fill the whole bar.
3. Solving with Bar ModelsDraw bar models to solve simple add and take-away word problems.Bar models help solve word problems. For '5 apples and 3 more,' the parts 5 and 3 make a whole of 8. For '9 grapes, eat 4,' the whole is 9, the eaten part is 4, and 5 are left. A bar model and a number sentence tell the same story — one drawn, one written.

Questions this course answers

Grounded in trusted sources

• PBS Kids — early math
• Khan Academy Kids
• NAEYC — early math learning
• Britannica Kids

Every Wunder lesson is built from real, reputable sources — never invented.

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