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## The Power of 37

Topics: Multiplication, patterns, Materials: Pencil & paper Common Core: 4.NBT.1, 4.NBT.5, 5.OA.1, 5.OA.2, 5.NBT.5, MP1, MP2, MP3, MP6, MP7, MP8. How does multiplying by 37 have this strange effect? This problems in multiplication is designed to give students the practice they need once they understand the basic idea of multiplication, with a context to provide motivation and deeper understanding. The …

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## Number Talks

Topics: Mental math, numerical fluency; argument & critique Materials: White board or projector Time:5 – 15 minutes Common Core: Variable, but especially MP3 This mental math routine creates powerful positive habits for students. Why We Love Number Talks Number talks don’t replace other instruction, but they are a powerful complement to it. They get all students involved, help them strengthen fluency, intuition, …

## Broken Calculators

Topics: Addition, Subtraction, Skip Counting, Multiplication, Logic Materials: Scratch paper and pencil, handouts (optional) Recommended Grade: 3, 4 Common Core: 3.OA.A.3, 3.OA.A.4, 3.OA.B.5, 3.OA.D.8, 3.OA.D.9, 4.OA.A.4, 4.OA.C.5, MP1, MP2, MP3, MP6, MP7, MP8 Something is wrong with the calculators in each lesson. Can students reach the target number despite the broken buttons? Why We Love Broken Calculators The premise is simple, but …

## Counterexamples

Topics: logic, deduction, mathematical argument, communication Materials: None Recommended Grades: K, 1, 2, 3, 4, 5, 6, 7, 8 Common Core: Variable, but especially MP3 Proving the teacher wrong. Rigorously. Why We Love Counterexamples Every kid loves to prove the teacher wrong. With Counterexamples, they get to do this in a productive way, and learn appropriate mathematical skepticism and communication …

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## Multiplication Table Sums

Topics: Multiplication, summation, patterns and structure Materials: Multiplication table, pencil and paper Grade: 4, 5, 6 Common Core: 4.OA.1, 4.OA.3, 4.OA.5, 4.NBT.5, 5.OA.2, 5.OA.3, 6.RP.1, 6.EE.1,  MP1, MP2, MP3, MP6, MP7, MP8. This is a great puzzle for kids who have some comfort with multiplication but still need to deepen their understanding. It gets them looking at the multiplication table …