🦕 DinosaursGrade 3Reading: grades 7-9MultiplicationRoundingAdditionSubtractionDivision
The Mystery of the Fossil Ridge Saboteur
Chaos struck the Cretaceous Basin Field Station when a rare Tyrannosaurus skull was tampered with right before the public unveiling. The culprit left behind clues across the dig site. Help Detective Vance decode the evidence and track down the suspect!
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 | Excavation Tool | Field Gear | Watch Wrist | Hat Color | Phobia |
|---|---|---|---|---|---|
| Dr. Dong Zhiming | Pneumatic Hammer | Thermal Imaging Visor | Left Wrist Watch | Olive Bucket Hat | Fear Of Dust Storms |
| Dr. Lindsay Zanno | Diamond Tip Scraper | Gps Survey Drone | Left Wrist Watch | Olive Bucket Hat | Fear Of Loud Noises |
| Dr. Barnum Brown | Laser Mapping Scanner | Gps Survey Drone | Right Wrist Watch | Olive Bucket Hat | Fear Of Dust Storms |
| Dr. Paul Sereno | Pneumatic Hammer | Gps Survey Drone | Left Wrist Watch | Brown Leather Cap | Fear Of Loud Noises |
| Dr. Kenneth Carpenter | Precision Air Scribe | Hydraulic Sample Pack | Right Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Jack Horner | Sonic Rock Chisel | Hydraulic Sample Pack | Right Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Ellie Sattler | Laser Mapping Scanner | Thermal Imaging Visor | Left Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Roy Chapman Andrews | Diamond Tip Scraper | Thermal Imaging Visor | Left Wrist Watch | Khaki Fedora | Fear Of Loud Noises |
| Prof. Othniel Marsh | Sonic Rock Chisel | Hydraulic Sample Pack | Right Wrist Watch | Olive Bucket Hat | Fear Of Dust Storms |
| Dr. Edward Cope | Laser Mapping Scanner | Hydraulic Sample Pack | Left Wrist Watch | Brown Leather Cap | Fear Of Loud Noises |
| Dr. Robert Bakker | Pneumatic Hammer | Hydraulic Sample Pack | Left Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Patricia Vickers | Diamond Tip Scraper | Thermal Imaging Visor | Right Wrist Watch | Olive Bucket Hat | Fear Of Heights |
| Dr. Xu Xing | Sonic Rock Chisel | Hydraulic Sample Pack | Left Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Angela Milner | Precision Air Scribe | Seismic Ground Sensor | Left Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Mary Anning | Sonic Rock Chisel | Hydraulic Sample Pack | Left Wrist Watch | Brown Leather Cap | Fear Of Dust Storms |
| Dr. Nizar Ibrahim | Pneumatic Hammer | Thermal Imaging Visor | Left Wrist Watch | Khaki Fedora | Fear Of Loud Noises |
| Dr. Alan Grant | Sonic Rock Chisel | Heavy Duty Magnifier | Left Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Rodolfo Coria | Laser Mapping Scanner | Thermal Imaging Visor | Left Wrist Watch | Olive Bucket Hat | Fear Of Heights |
| Dr. Thomas Holtz | Diamond Tip Scraper | Gps Survey Drone | Right Wrist Watch | Khaki Fedora | Fear Of Dust Storms |
| Dr. Kristina Curry | Sonic Rock Chisel | Thermal Imaging Visor | Left Wrist Watch | Khaki Fedora | Fear Of Loud Noises |
| Dr. Anusuya Chinsamy | Precision Air Scribe | Seismic Ground Sensor | Left Wrist Watch | Brown Leather Cap | Fear Of Dust Storms |
Clue 1
Multiplication facts (1-12)
At the quarry grid, researchers organized bone fragments into equal rows to compute total fossil yields.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
N
4
99
24
10
27
108
84
48
8
5
84
44
27
40
N
4
1
64
1
10
63
50
27
132
64
99
8
N
4
48
27
5
5
24
10
132
15
10
N
4
10
2 × 2 =N
8 × 5 =G
9 × 12 =V
11 × 9 =O
1 × 5 =T
9 × 7 =R
4 × 2 =U
5 × 3 =C
8 × 8 =F
4 × 11 =M
12 × 7 =Y
8 × 6 =D
2 × 12 =H
3 × 9 =A
12 × 11 =S
10 × 5 =W
1 × 1 =I
1 × 10 =E
0/18 letters found
Clue 2
Rounding
The digital station readout showed approximate sediment depth figures rounded to the nearest ten.
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
4000
3000
2000
60
700
60
6000
2000
50
T
4000
8000
800
40
2000
90
8000
90
T
4000
50
3000
800
300
T
4000
3000
2000
400
40
9000
2000
70
T
4000
8000
40
400
60
T
4000
Round 3,951 to the nearest thousandT
Round 6,118 to the nearest thousandP
Round 397 to the nearest hundredI
Round 8,449 to the nearest thousandW
Round 3,291 to the nearest thousandH
Round 67 to the nearest tenF
Round 326 to the nearest hundredN
Round 744 to the nearest hundredU
Round 94 to the nearest tenA
Round 2,469 to the nearest thousandE
Round 39 to the nearest tenR
Round 49 to the nearest tenC
Round 9,490 to the nearest thousandL
Round 64 to the nearest tenS
Round 763 to the nearest hundredO
0/15 letters found
Clue 3
Addition
The field lab technician tallied all newly cataloged specimen bags brought in from the North Trench.
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
637
828
367
676
470
825
364
518
878
T
637
668
825
367
935
226
828
367
406
204
935
470
985
T
637
985
T
637
265
518
864
985
T
637
204
518
T
637
367
935
324 + 313 =T
115 + 89 =A
85 + 141 =W
165 + 199 =P
433 + 243 =C
377 + 608 =S
588 + 347 =D
154 + 316 =U
435 + 443 =I
490 + 335 =L
219 + 148 =E
484 + 344 =H
228 + 178 =N
184 + 81 =O
188 + 330 =R
267 + 401 =F
268 + 596 =M
0/17 letters found
Clue 4
Subtraction
Comparing total excavated crates to remaining inventory revealed how many sample boxes were taken.
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
856
202
476
A
856
202
152
348
294
253
244
429
A
856
736
A
856
874
253
429
244
469
469
294
253
517
294
A
856
429
186
476
294
348
244
874
874
152
334
1078 - 222 =A
406 - 58 =F
811 - 75 =W
698 - 181 =N
380 - 46 =L
899 - 25 =S
566 - 272 =E
224 - 72 =I
556 - 87 =P
470 - 284 =T
488 - 59 =R
429 - 185 =O
852 - 376 =H
283 - 81 =K
569 - 316 =D
0/15 letters found
Clue 5
Division facts (1-12) — the last clue
The expedition lead split the remaining field supplies equally among the research teams.
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
96 ÷ 8 = ?
50 ÷ 10 = ?
44 ÷ 4 = ?
63 ÷ 7 = ?
21 ÷ 7 = ?
40 ÷ 10 = ?
120 ÷ 12 = ?
56 ÷ 7 = ?
24 ÷ 4 = ?
8 ÷ 8 = ?
20 ÷ 10 = ?
Step 2 — cross out the sentence with each answer
1.The villain chiseled with a precision air scribe, then scouted the perimeter with a thermal imaging visor.
2.The villain scraped with a diamond tip scraper, then scouted the perimeter with a thermal imaging visor.
3.The villain scraped with a diamond tip scraper, then loaded soil into a hydraulic sample pack.
4.The villain swept a laser mapping scanner over the grid, then loaded soil into a hydraulic sample pack.
5.The villain used a sonic rock chisel to crack the plaster, then loaded soil into a hydraulic sample pack.
6.The villain fired up a pneumatic hammer near the specimen, then monitored vibrations with a seismic ground sensor.
7.The villain swept a laser mapping scanner over the grid, then scouted the perimeter with a thermal imaging visor.
8.The villain swept a laser mapping scanner over the grid, then launched a gps survey drone overhead.
9.The villain scraped with a diamond tip scraper, then launched a gps survey drone overhead.
10.The villain swept a laser mapping scanner over the grid, then inspected the bone structure using a heavy duty magnifier.
11.The villain chiseled with a precision air scribe, then monitored vibrations with a seismic ground sensor.
12.The villain fired up a pneumatic hammer near the specimen, then loaded soil into a hydraulic sample pack.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Fossil Ridge Saboteur
Culprit: Dr. Ellie Sattler (Laser Mapping Scanner · Thermal Imaging Visor · Left Wrist Watch · Khaki Fedora · Fear Of Dust Storms)
- Clue 1 (Multiplication facts (1-12)): "NO HEAVY DUTY MAGNIFIER WAS FOUND AT THE SCENE"2 × 2 = 4 (N) · 8 × 5 = 40 (G) · 9 × 12 = 108 (V) · 11 × 9 = 99 (O) · 1 × 5 = 5 (T) · 9 × 7 = 63 (R) · 4 × 2 = 8 (U) · 5 × 3 = 15 (C) · 8 × 8 = 64 (F) · 4 × 11 = 44 (M) · 12 × 7 = 84 (Y) · 8 × 6 = 48 (D) · 2 × 12 = 24 (H) · 3 × 9 = 27 (A) · 12 × 11 = 132 (S) · 10 × 5 = 50 (W) · 1 × 1 = 1 (I) · 1 × 10 = 10 (E)
- Clue 2 (Rounding): "THE SUSPECT WORE A WATCH ON THEIR LEFT WRIST"Round 3,951 to the nearest thousand = 4000 (T) · Round 6,118 to the nearest thousand = 6000 (P) · Round 397 to the nearest hundred = 400 (I) · Round 8,449 to the nearest thousand = 8000 (W) · Round 3,291 to the nearest thousand = 3000 (H) · Round 67 to the nearest ten = 70 (F) · Round 326 to the nearest hundred = 300 (N) · Round 744 to the nearest hundred = 700 (U) · Round 94 to the nearest ten = 90 (A) · Round 2,469 to the nearest thousand = 2000 (E) · Round 39 to the nearest ten = 40 (R) · Round 49 to the nearest ten = 50 (C) · Round 9,490 to the nearest thousand = 9000 (L) · Round 64 to the nearest ten = 60 (S) · Round 763 to the nearest hundred = 800 (O)
- Clue 3 (Addition): "THE CULPRIT FLED WHEN A DUST STORM STARTED"324 + 313 = 637 (T) · 115 + 89 = 204 (A) · 85 + 141 = 226 (W) · 165 + 199 = 364 (P) · 433 + 243 = 676 (C) · 377 + 608 = 985 (S) · 588 + 347 = 935 (D) · 154 + 316 = 470 (U) · 435 + 443 = 878 (I) · 490 + 335 = 825 (L) · 219 + 148 = 367 (E) · 484 + 344 = 828 (H) · 228 + 178 = 406 (N) · 184 + 81 = 265 (O) · 188 + 330 = 518 (R) · 267 + 401 = 668 (F) · 268 + 596 = 864 (M)
- Clue 4 (Subtraction): "A KHAKI FEDORA WAS DROPPED NEAR THE FOSSIL"1078 - 222 = 856 (A) · 406 - 58 = 348 (F) · 811 - 75 = 736 (W) · 698 - 181 = 517 (N) · 380 - 46 = 334 (L) · 899 - 25 = 874 (S) · 566 - 272 = 294 (E) · 224 - 72 = 152 (I) · 556 - 87 = 469 (P) · 470 - 284 = 186 (T) · 488 - 59 = 429 (R) · 429 - 185 = 244 (O) · 852 - 376 = 476 (H) · 283 - 81 = 202 (K) · 569 - 316 = 253 (D)
- Clue 5 (Division facts (1-12)): surviving statement (box 7) → Dr. Ellie Sattler96 ÷ 8 = 12 · 50 ÷ 10 = 5 · 44 ÷ 4 = 11 · 63 ÷ 7 = 9 · 21 ÷ 7 = 3 · 40 ÷ 10 = 4 · 120 ÷ 12 = 10 · 56 ÷ 7 = 8 · 24 ÷ 4 = 6 · 8 ÷ 8 = 1 · 20 ÷ 10 = 2
About this mystery
- Grade level
- Grade 3 math
- Math topics
- Multiplication, Rounding, Addition, Subtraction, Division
- Reading level
- grades 7-9
- Theme
- The Mystery of the Fossil Ridge Saboteur — set in Cretaceous Basin Field Station
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects