Warm-up / extension problem with a “low floor – high ceiling”: every learner can participate, but the task still stretches advanced students.
Goal: write every integer from 1 to 20 (and beyond) using exactly four 4’s and any operations the class has agreed upon.
Strategies mentioned
• Basic operations only: students first try without exponents, parentheses or square roots.
• Gradual introduction of higher tools once they are needed:
– Square root 4=2 (allows quick creation of 2,8,16,…).
– Factorial “four-bang” 4!=4×3×2×1=24.
– Exponents: 42=16,43=64,44=256.
Sample solutions discussed
• 44+4+4=3 (no parentheses needed if division precedes addition).
• (4+4+4)÷4÷4=3 (parentheses then two successive divisions).
Pedagogical use
• Launches Order-of-Operations conversation (natural need for PEMDAS/GEMDAS).
• Leads organically into square roots, exponents, factorial, inverse operations.
Order of Operations & Step-by-Step Discipline
Students perform one operation at a time, circling the part they are about to evaluate.
After every step they copy the entire line again – builds habits for algebraic manipulation.
Emphasise multiplication & division before addition & subtraction, and equal priority left-to-right.
Teacher writes only one equal sign – the final one – to prevent strings of false equalities.
Worked classroom example
Problem: 5+3×2−9÷3.
Circle 3×2, compute 6, rewrite full line.
Circle 9÷3, compute 3, rewrite full line.
Now only + and − remain; proceed left-to-right.
Introducing Exponents & Roots
Connect to students’ idea of “repeated multiplication” (analogy: multiplication = repeated addition).
Keep exponents small (2nd,3rd,4th power) for computational comfort.
“Going backwards” (inverse operations) is conceptually hard; use physical metaphors (walk forward/back).
Factorial (!)
Notation n! read as “n-bang.”
Definition, e.g. 4!=4×3×2×1=24
Adds another handy constant for the Four-Fours list and foreshadows permutations/combinatorics.
Evolution of the Multiplication Symbol
From × in early grades → ⋅ in middle school → implied juxtaposition in algebra (e.g. 2x).
Classroom ritual “R.I.P. ×” helps students let go of the × and understand why • (dot) is preferred (avoids conflict with the variable x).
Division Notation
Stress horizontal fraction bar only; avoid slanted bars (e.g. computer fonts) – prepares students for complex algebraic fractions.
Reinforce that 416, 16÷4, and the long-division “house” all represent the same operation.
Rules / Phrases That Expire (Language Precision)
“Addition & multiplication make numbers bigger” – false once fractions/negatives appear (e.g. 24×21=12).
“Subtraction & division make numbers smaller” – similarly limited.
→ In early grades specify whole numbers only, and revisit explicitly when new number types arise.
“To multiply by 10 just tag on a 0” – fails for decimals (43.5×10=43.50 but 435).
→ Teach as a place-value shift.
Equal sign misconception: many students read “= means ‘find the answer.’”
• Use open sentences like 14+□=48+◊ to emphasise “is the same as” (relational meaning).
Number-Sense Routines (Daily/Weekly)
Which One Doesn’t Belong (WODB)
• Strengthens mathematical vocabulary and precise justification.
• Every option can be correct with a valid reason.
Estimation Routine
• Weekly exercise; research shows a high correlation between estimation skill and later math success.
• Fold brief estimation checks into any lesson.
Differentiation & Homework Philosophy
All students aim for the same conceptual bar; differentiation lies in supports and entry points, not in lowering the task.
Visual link: shade parts of a rectangle so students see the whole as the sum of parts.
Ratio-Shading Task (Don Stewart “ratio shading” sheets)
Grid (e.g. 3×4) represents the whole.
Steps students discover / teacher lightly guides:
Add partsa+b to find total parts.
Count squares in grid (e.g. 12); divide by total parts → squares per part.
Shade first part squares one colour, second part squares another.
Order matters: 1:3=3:1.
Fractional parts (e.g. 221:121) force students to subdivide rows/columns or think in half-rows.
Extension sheet with tougher ratios available for fast finishers.
Equivalent Ratios & Double Number Lines
Visual tool: two parallel number lines incremented identically.
• Top line tracks first part, bottom line second part.
• Start with anchor ratio (e.g. 2:3 at same position).
• Extend equal “chunks” to generate 4:6,6:9,8:12,…
Supports shift to proportion reasoning in 7th grade.
Rates & Unit Rates (Introduced in 6th)
Rate = ratio with attached units (e.g. 5 pencils:$20).
Unit rate: divide to get “per one” (e.g. $4 per pencil).
Double number line again useful.
Preparing for 7th Grade Proportions
Proportions (equations of equivalent ratios) delayed until after the 7th-grade algebra block for better readiness.
Example 7th-grade tie-in: x5=3220, cross-product method grounded in earlier ratio work.
Notation, Language & Visual Consistency Reminders
Always write the fraction bar horizontal.
Encourage multiple representations (verbal, numeric, pictorial) of any new idea.
Keep language precise: say “simplify” a fraction, not “reduce.”
Fraction isn’t shrinking; it’s wearing a different “costume.”
Homework, Resources & Teacher Support
Sharon will upload complete 6th-grade scope-and-sequence + full lesson plans, homework sets, and links on Canvas (shared drive for non-PITEP participants).
Teachers invited to email for specific unit materials or emergency homework two months down the line.
Recommended external site: Don Stewart’s Median blog (rich ratio visuals, assorted tasks for all grades).
Article: “13 Rules That Expire” (will be placed in Resources folder) – highlights common sayings that later mislead.
Closing Thoughts Shared in Session
Constantly watch students’ written work for “mathematical nonsense” (strings of equals, random operations).
Small diagnostic prompts (e.g. 12+□=5+7) reveal misconceptions quickly.
Flexibility with symbols, operations, and representations is cultivated deliberately – not left to chance.