🔎 Pencils Stolen from the FronGrade 9Reading: grades 7-9Two-step equationsMulti-step word problemsExponentsSquare roots
The Case of the Missing Ticonderogas
Right before the weekly pop quiz, Mrs. Gable discovered that her entire stash of premium, neon-hued, ultra-sharp pencils had vanished from the front of the room. A single mystery note was left in their place. Help us solve the equations to catch the culprit before the next class bell rings!
Suspects
Possible suspects
Cross off a row as each clue rules it out. On screen, tap a row.
21 of 21 still in play
| Name | Desk Alibi | Stashed Item | Writing Hand | Hair Style | Squealer Sound |
|---|---|---|---|---|---|
| Kai | borrowing an eraser | mesh side pocket | right handed writer | messy bun | squeaky sneaker scuff |
| Yara | borrowing an eraser | zippered pencil pouch | right handed writer | messy bun | squeaky sneaker scuff |
| Zane | borrowing an eraser | mesh side pocket | right handed writer | buzz cut | squeaky sneaker scuff |
| Devon | turning in a scratch paper | zippered pencil pouch | right handed writer | messy bun | pencil sharpener hum |
| Charlie | sharpening a colored pencil | giant winter boot | left handed writer | messy bun | velcro ripping sound |
| Wyatt | turning in a scratch paper | mesh side pocket | left handed writer | messy bun | velcro ripping sound |
| Val | asking for a bathroom pass | spiral notebook | right handed writer | messy bun | squeaky sneaker scuff |
| Jordan | asking for a bathroom pass | giant winter boot | right handed writer | messy bun | velcro ripping sound |
| Finley | stretching near the window | mesh side pocket | right handed writer | buzz cut | pencil sharpener hum |
| Logan | sharpening a colored pencil | spiral notebook | left handed writer | messy bun | pencil sharpener hum |
| Isaac | sharpening a colored pencil | giant winter boot | right handed writer | messy bun | pencil sharpener hum |
| Toby | asking for a bathroom pass | giant winter boot | left handed writer | buzz cut | pencil sharpener hum |
| Gavin | turning in a scratch paper | spiral notebook | right handed writer | messy bun | pencil sharpener hum |
| Sam | asking for a bathroom pass | mesh side pocket | left handed writer | messy bun | squeaky sneaker scuff |
| Taylor | stretching near the window | hollowed out textbook | right handed writer | ponytail | velcro ripping sound |
| Parker | stretching near the window | mesh side pocket | right handed writer | buzz cut | squeaky sneaker scuff |
| Alex | sharpening a colored pencil | hollowed out textbook | right handed writer | ponytail | squeaky sneaker scuff |
| Harper | sharpening a colored pencil | spiral notebook | right handed writer | messy bun | squeaky sneaker scuff |
| Morgan | borrowing an eraser | hollowed out textbook | right handed writer | messy bun | velcro ripping sound |
| Elliot | stretching near the window | giant winter boot | right handed writer | messy bun | squeaky sneaker scuff |
| Quinn | borrowing an eraser | hollowed out textbook | right handed writer | messy bun | pencil sharpener hum |
Clue 1
Two-step equations
Mrs. Gable needs to find out how many pencil packs were opened before the quiz. She counts the remaining boxes, multiplies by the pack size, and subtracts the damaged ones to reveal the first clue.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
T
14
13
22
T
14
13
11
22
12
10
11
10
2
20
T
14
13
11
10
22
T
14
13
22
9
11
2
21
8
11
2
T
14
22
7
15
20
20
T
14
7x + 1 = 99, x =T
8x + 7 = 23, x =N
7x + 11 = 88, x =I
5x + 8 = 43, x =R
3x + 1 = 28, x =M
5x + 10 = 120, x =E
5x + 9 = 49, x =W
3x + 9 = 48, x =H
5x + 2 = 52, x =D
2x + 6 = 48, x =A
5x + 4 = 79, x =B
9x + 8 = 188, x =O
9x + 5 = 113, x =F
0/13 letters found
Clue 2
Multi-step word problems
To find the locker combination that holds the security footage, we must solve a formula matching the total weight of the textbooks plus a fixed locker key weight.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Awitnesssawthevillainwas .
R
60
8
17
49
6
49
80
14
D
E
D
W
R
60
8
6
E
R
60
There were 193 protractor in all. 1 Math Club used 13 protractor each. The other 3 Math Club shared the rest equally. How many protractor did each of the other Math Club get?R
There were 107 protractor in all. 2 Math Club used 28 protractor each. The other 3 Math Club shared the rest equally. How many protractor did each of the other Math Club get?G
Hall Monitor earned 8 pink eraser in each of 6 rounds, plus 44 bonus pink eraser. Then 12 pink eraser were lost. How many pink eraser are left?A
There were 330 pink eraser in all. 36 pink eraser were set aside. The rest were shared equally among 6 Math Club. How many pink eraser did each get?H
Hall Monitor collected 33 graphite pencil in the morning and 23 graphite pencil in the afternoon, then split them equally among 4 Math Club. How many graphite pencil did each get?N
There were 148 graphite pencil in all. 4 Math Club used 31 graphite pencil each. The other 3 Math Club shared the rest equally. How many graphite pencil did each of the other Math Club get?I
There were 22 protractor in all. 10 protractor were set aside. The rest were shared equally among 2 Math Club. How many protractor did each get?T
0/7 letters found
Clue 3
Exponents
The suspect ran down the hallway, leaving footprints that multiplied exponentially at each turn. Calculating the total growth rate gives us the next scrap of evidence.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
T
9
625
225
T
9
625
49
225
64
289
125
128
225
8
225
512
T
9
625
225
49
8
225
169
8
441
169
T
9
T
9
625
225
441
121
144
225
169
400
3^2 =T
12^2 =U
2^3 =R
15^2 =E
8^2 =F
20^2 =K
2^7 =V
11^2 =Q
5^4 =H
5^3 =O
17^2 =C
13^2 =A
7^2 =I
8^3 =D
21^2 =S
0/15 letters found
Clue 4
Square roots
The principal wants to search a perfectly square section of the classroom floor tiles. Finding the side length of this area points directly to a hair clue.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
A
10
12
18
4
A
10
8
22
2
3
6
A
10
21
4
3
4
2
11
A
10
11
19
12
12
17
25
15
8
23
A
10
12
3
2
15
8
22
sqrt(100) =A
sqrt(36) =H
sqrt(484) =D
sqrt(16) =R
sqrt(144) =S
sqrt(625) =B
sqrt(324) =T
sqrt(121) =M
sqrt(289) =Y
sqrt(361) =E
sqrt(529) =W
sqrt(9) =F
sqrt(4) =O
sqrt(64) =N
sqrt(441) =I
sqrt(225) =U
0/16 letters found
Clue 5
Two-step equations — the last clue
The hall monitor tracks the hall pass usage. A simple two-step algebraic equation reveals exactly how many minutes the suspect was out of their seat.
First solve each problem. Then find each answer in the list below and cross that sentence out. One sentence will be left — that's exactly what the villain did!
Step 1 — solve these
3x + 12 = 33, x = ?
2x + 6 = 30, x = ?
8x + 3 = 75, x = ?
8x + 3 = 83, x = ?
9x + 8 = 107, x = ?
3x + 5 = 11, x = ?
7x + 11 = 39, x = ?
7x + 8 = 29, x = ?
5x + 9 = 49, x = ?
3x + 7 = 25, x = ?
2x + 7 = 17, x = ?
Step 2 — cross out the sentence with each answer
1.The villain crept to the front desk, then stuffed the graphite into a binder.
2.The villain snuck behind the teacher's podium, then concealed the pencils under a hall pass.
3.The villain distracted the front row, then stuffed the graphite into a binder.
4.The villain distracted the front row, then slipped the pencils under a notebook.
5.The villain waited for the lights to dim, then stuffed the graphite into a binder.
6.The villain snuck behind the teacher's podium, then slid the loot into a backpack pocket.
7.The villain waited for the lights to dim, then slid the loot into a backpack pocket.
8.The villain snuck behind the teacher's podium, then passed the pencils to an accomplice.
9.The villain tipped over the pencil cup, then stuffed the graphite into a binder.
10.The villain tipped over the pencil cup, then slipped the pencils under a notebook.
11.The villain waited for the lights to dim, then concealed the pencils under a hall pass.
12.The villain waited for the lights to dim, then passed the pencils to an accomplice.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Case of the Missing Ticonderogas
Culprit: Harper (sharpening a colored pencil · spiral notebook · right handed writer · messy bun · squeaky sneaker scuff)
- Clue 1 (Two-step equations): "THE THIEF DID NOT HIDE THEM IN A WINTER BOOT"7x + 1 = 99, x = 14 (T) · 8x + 7 = 23, x = 2 (N) · 7x + 11 = 88, x = 11 (I) · 5x + 8 = 43, x = 7 (R) · 3x + 1 = 28, x = 9 (M) · 5x + 10 = 120, x = 22 (E) · 5x + 9 = 49, x = 8 (W) · 3x + 9 = 48, x = 13 (H) · 5x + 2 = 52, x = 10 (D) · 2x + 6 = 48, x = 21 (A) · 5x + 4 = 79, x = 15 (B) · 9x + 8 = 188, x = 20 (O) · 9x + 5 = 113, x = 12 (F)
- Clue 2 (Multi-step word problems): "RIGHT HANDED WRITER"There were 193 protractor in all. 1 Math Club used 13 protractor each. The other 3 Math Club shared the rest equally. How many protractor did each of the other Math Club get? = 60 (R) · There were 107 protractor in all. 2 Math Club used 28 protractor each. The other 3 Math Club shared the rest equally. How many protractor did each of the other Math Club get? = 17 (G) · Hall Monitor earned 8 pink eraser in each of 6 rounds, plus 44 bonus pink eraser. Then 12 pink eraser were lost. How many pink eraser are left? = 80 (A) · There were 330 pink eraser in all. 36 pink eraser were set aside. The rest were shared equally among 6 Math Club. How many pink eraser did each get? = 49 (H) · Hall Monitor collected 33 graphite pencil in the morning and 23 graphite pencil in the afternoon, then split them equally among 4 Math Club. How many graphite pencil did each get? = 14 (N) · There were 148 graphite pencil in all. 4 Math Club used 31 graphite pencil each. The other 3 Math Club shared the rest equally. How many graphite pencil did each of the other Math Club get? = 8 (I) · There were 22 protractor in all. 10 protractor were set aside. The rest were shared equally among 2 Math Club. How many protractor did each get? = 6 (T)
- Clue 3 (Exponents): "THE THIEF COVERED THEIR EARS AT THE SQUEAK"3^2 = 9 (T) · 12^2 = 144 (U) · 2^3 = 8 (R) · 15^2 = 225 (E) · 8^2 = 64 (F) · 20^2 = 400 (K) · 2^7 = 128 (V) · 11^2 = 121 (Q) · 5^4 = 625 (H) · 5^3 = 125 (O) · 17^2 = 289 (C) · 13^2 = 169 (A) · 7^2 = 49 (I) · 8^3 = 512 (D) · 21^2 = 441 (S)
- Clue 4 (Square roots): "A STRAND OF HAIR FROM A MESSY BUN WAS FOUND"sqrt(100) = 10 (A) · sqrt(36) = 6 (H) · sqrt(484) = 22 (D) · sqrt(16) = 4 (R) · sqrt(144) = 12 (S) · sqrt(625) = 25 (B) · sqrt(324) = 18 (T) · sqrt(121) = 11 (M) · sqrt(289) = 17 (Y) · sqrt(361) = 19 (E) · sqrt(529) = 23 (W) · sqrt(9) = 3 (F) · sqrt(4) = 2 (O) · sqrt(64) = 8 (N) · sqrt(441) = 21 (I) · sqrt(225) = 15 (U)
- Clue 5 (Two-step equations): surviving statement (box 1) → Harper3x + 12 = 33, x = 7 · 2x + 6 = 30, x = 12 · 8x + 3 = 75, x = 9 · 8x + 3 = 83, x = 10 · 9x + 8 = 107, x = 11 · 3x + 5 = 11, x = 2 · 7x + 11 = 39, x = 4 · 7x + 8 = 29, x = 3 · 5x + 9 = 49, x = 8 · 3x + 7 = 25, x = 6 · 2x + 7 = 17, x = 5
About this mystery
- Grade level
- Grade 9 math
- Math topics
- Two-step equations, Multi-step word problems, Exponents, Square roots
- Reading level
- grades 7-9
- Theme
- The Case of the Missing Ticonderogas — set in Room 302 of Oak Creek Middle School
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects