Unit 1 · Teacher Resource

Unit 1 Projects — Teacher Answer Key

Worked solutions for both versions of the Unit 1 culminating project (Number Sense). Covers Version A: Block Party Planner and Version B: Build-a-Bot Budget Lab.

For teachers — worked solutions using the default values. Students who change the inputs will get different (but similarly-structured) answers. Every number on this page has been verified by tracing the exact formula each calculator uses. Quick-check answers are deterministic (hard-coded in the JS) and do not change regardless of inputs.
Version A  ·  Design & Build

🎉 Block Party Planner

Standards: 6.NS.2 • 6.NS.3 • 6.NS.4 • $300 budget scenario

1 Phase 1 — Build Identical Goodie Bags (GCF · 6.NS.4)

InputDefault ValueWorked SolutionFinal Answer
Number of stickers 48
Factors of 48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48
Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
GCF(48, 36) = 12

Each bag: 48 ÷ 12 = 4 stickers
Each bag: 36 ÷ 12 = 3 granola bars
12 goodie bags
(4 stickers + 3 bars each)
Number of granola bars 36

2 Phase 2 — Sync the Entertainment Schedule (LCM · 6.NS.4)

InputDefault ValueWorked SolutionFinal Answer
DJ hype song every (min) 6
Multiples of 6: 6, 12, 18, 24, 30 …
Multiples of 8: 8, 16, 24, 32 …

First common multiple = 24
Verification: 24 ÷ 6 = 4 (4 songs) ✓
              24 ÷ 8 = 3 (3 bursts) ✓
Every 24 minutes
Bubble machine every (min) 8

3 Phase 3 — Track the Budget to the Penny (Decimal Operations · 6.NS.3)

CategoryDefault AmountRunning Total
Food & drinks$124.50$124.50
Decorations$38.75$163.25
Games & prizes$67.20$230.45
Music & supplies$45.00$275.45
Total spent
124.50
 38.75
 67.20
+ 45.00
──────
275.45
Remaining budget $300.00 − $275.45 = $24.55 remaining ✓ Under budget

4 Phase 4 — Set a Fair Price Per Person (Division · 6.NS.2 · 6.NS.3)

InputDefault ValueWorked SolutionFinal Answer
Total shared cost $275.40
$275.40 ÷ 36 guests

36 × 7 = 252
275.40 − 252.00 = 23.40
36 × 0.65 = 23.40
   → $7.65 per guest

Check: 36 × $7.65 = $275.40 ✓
$7.65 per guest
Number of guests 36
Quick-Check Problem (hard-coded, always the same): A pack of 144 cups is shared equally among 6 tables. How many cups per table?
144 ÷ 6 = 24
Check: 6 × 24 = 144 ✓
Answer: 24 cups per table

Sample Expert Written Pitch (Final Deliverable)

"In our block party plan, we will make 12 identical goodie bags because GCF(48, 36) = 12 — each bag holds 4 stickers and 3 granola bars with nothing left over. The DJ and bubble machine will sync up every 24 minutes (LCM of 6 and 8), which is when we should schedule the biggest crowd moment. Our total cost is $275.45 — adding $124.50 + $38.75 + $67.20 + $45.00 — which keeps us $24.55 under the $300 budget. Splitting the $275.40 shared cost among 36 guests gives a fair share of $7.65 per person, and we verified this with the division check: 36 × $7.65 = $275.40."

Sample 4 / 3 / 2 Rubric Scoring Notes

Expert (4) responses demonstrate: GCF and LCM both stated correctly with reasoning shown (e.g., listing factors or multiples); budget total accurate to the penny and explicitly under $300; cost-per-guest calculation shown step by step AND the quick-check (144 ÷ 6 = 24) answered correctly; written pitch names every calculated number with correct units and connects each number to its mathematical operation.

Proficient (3): All four numerical answers correct but written pitch may omit one number or reasoning step.

Developing (2): At least two phases attempted; minor decimal/place-value or factor errors; pitch is present but incomplete.


Version B  ·  Real-World Investigation

🤖 Build-a-Bot Budget Lab

Standards: 6.NS.2 • 6.NS.3 • 6.NS.4 • $500 budget scenario

1 Phase 1 — Price the Parts Order (Decimal Multiplication · 6.NS.3)

PartUnit PriceQuantityWorked SolutionLine Total
Motor $18.75 4 $18.75 × 4 = (18 × 4) + (0.75 × 4) = 72.00 + 3.00 = $75.00 $75.00
Wheel set $6.40 6 $6.40 × 6 = (6 × 6) + (0.40 × 6) = 36.00 + 2.40 = $38.40 $38.40
Sensor $12.25 3 $12.25 × 3 = (12 × 3) + (0.25 × 3) = 36.00 + 0.75 = $36.75 $36.75
Parts subtotal
$75.00 + $38.40 + $36.75 = $150.15
$150.15

2 Phase 2 — Split the Cost Fairly (Division · 6.NS.2)

InputDefault ValueWorked SolutionFinal Answer
Total shared cost $384.00
$384.00 ÷ 8 members

8 × 48 = 384
   → $48.00 each

Check: 8 × $48.00 = $384.00 ✓
$48.00 per teammate
Team members 8

3 Phase 3 — Organize the Toolkit (GCF · 6.NS.4)

InputDefault ValueWorked SolutionFinal Answer
Screws 72
Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54
GCF(72, 54) = 18

Each kit: 72 ÷ 18 = 4 screws
Each kit: 54 ÷ 18 = 3 bolts
18 toolkits
(4 screws + 3 bolts each)
Bolts 54

4 Phase 4 — Are You Under $500? (Budget Check · 6.NS.3)

CategoryDefault AmountRunning Total
Parts subtotal$160.75$160.75
Travel$210.50$371.25
Snacks$64.80$436.05
Total cost
160.75
210.50
+ 64.80
──────
436.05
Remaining budget $500.00 − $436.05 = $63.95 remaining ✓ Under $500 budget
Quick-Check Problem (hard-coded, always the same): A reel of 96 zip ties is shared among 6 robots. How many per robot?
96 ÷ 6 = 16
Check: 6 × 16 = 96 ✓
Answer: 16 zip ties per robot

Sample Expert Written Memo (Final Deliverable)

"Coach, our parts subtotal is $150.15 — calculated by multiplying each unit price by its quantity and adding: $75.00 (motors) + $38.40 (wheels) + $36.75 (sensors). Split among 8 team members, each person owes $48.00 for shared costs of $384.00 (÷ 8 = $48.00). Using GCF(72, 54) = 18, we can build 18 identical toolkits, each containing 4 screws and 3 bolts with no leftovers. Our full trip total is $436.05, which is $63.95 under the $500 budget, so I recommend approving this order."

Sample 4 / 3 / 2 Rubric Scoring Notes

Expert (4) responses demonstrate: All three line totals computed correctly with decimal place value maintained; cost-per-share computed correctly AND verified with a multiplication check; GCF of 72 and 54 correctly identified as 18, with kit contents (4 screws, 3 bolts) stated; full budget total ($436.05) compared explicitly to $500 with the remaining ($63.95) named; memo gives a clear recommendation (approve or revise) and cites every number computed.

Proficient (3): All four numerical results correct; memo uses most numbers but may skip the multiplication check or omit one kit-content detail.

Developing (2): At least two phases attempted; minor decimal or GCF errors; memo present but recommendation is vague or numbers are missing.