Grade 1Reading: grades 1-2AdditionSubtractionSkip countingPlace valueMissing addends
The Mystery of the Missing Golden Compass
Someone snuck into the main treehouse and took the Golden Compass! Use your math skills and clue decode ring to find the sneaky camper who did it.
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 | Main Gear | Badge | Dominant Hand | Hair Color | Weakness |
|---|---|---|---|---|---|
| Luke Leaf | Flashlight | Whistle Badge | Left Handed | Red Hair | Loud Whistles |
| Pip Pathfinder | Map | Whistle Badge | Right Handed | Brown Hair | Squeaky Toys |
| Chloe Camper | Map | Night Goggles | Right Handed | Brown Hair | Loud Whistles |
| Sammy Scout | Compass | Night Goggles | Right Handed | Brown Hair | Loud Whistles |
| Owen Outdoors | Map | Glider Cape | Right Handed | Brown Hair | Loud Whistles |
| Ben Voyager | Map | Decoder Ring | Right Handed | Blonde Hair | Bright Lights |
| Finn Forest | Binoculars | Whistle Badge | Left Handed | Brown Hair | Loud Whistles |
| Zack Hiker | Binoculars | Tracker Boots | Right Handed | Blonde Hair | Loud Whistles |
| Maya Ranger | Compass | Decoder Ring | Left Handed | Brown Hair | Bright Lights |
| Jack Jungle | Compass | Decoder Ring | Right Handed | Blonde Hair | Squeaky Toys |
| Leo Explorer | Compass | Night Goggles | Left Handed | Brown Hair | Loud Whistles |
| Cody Canyon | Binoculars | Glider Cape | Right Handed | Brown Hair | Squeaky Toys |
| Lily Lake | Flashlight | Whistle Badge | Right Handed | Blonde Hair | Squeaky Toys |
| Sophia Sprout | Flashlight | Glider Cape | Left Handed | Brown Hair | Loud Whistles |
| Daisy Pioneer | Binoculars | Night Goggles | Right Handed | Blonde Hair | Loud Whistles |
| Ava Alpine | Flashlight | Night Goggles | Right Handed | Brown Hair | Loud Whistles |
| Ruby Rover | Binoculars | Decoder Ring | Left Handed | Brown Hair | Loud Whistles |
| Noah Nav | Flashlight | Glider Cape | Right Handed | Blonde Hair | Loud Whistles |
| Milo Meadow | Map | Whistle Badge | Right Handed | Red Hair | Loud Whistles |
| Ella Environmentalist | Binoculars | Night Goggles | Right Handed | Red Hair | Squeaky Toys |
| Ivy Trail | Grappling Hook | Tracker Boots | Left Handed | Brown Hair | Loud Whistles |
Clue 1
Addition
Count the total trail snacks collected by the campers to unlock 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
17
6
12
8
19
12
13
14
20
11
12
8
19
11
T
17
7
12
13
9
T
17
9
13
18
14
12
9
3
11
11
T
17
8
12 + 5 =T
1 + 2 =B
6 + 14 =D
6 + 5 =O
7 + 7 =K
3 + 5 =S
12 + 6 =C
3 + 4 =W
4 + 2 =H
4 + 5 =R
9 + 4 =A
10 + 9 =N
7 + 5 =E
0/13 letters found
Clue 2
Subtraction
Some map scrolls went missing from the camp chest. Subtract to find what remains.
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
2
6
10
18
18
T
14
11
17
7
8
T
14
15
15
2
18
1
19
16
6
10
T
14
2
19
8
13
6
13
3
17
7
11
19 - 5 =T
18 - 3 =S
12 - 1 =P
4 - 1 =G
20 - 4 =L
9 - 7 =H
14 - 7 =I
7 - 6 =W
20 - 1 =A
15 - 5 =F
20 - 2 =O
17 - 9 =N
20 - 3 =R
15 - 9 =E
19 - 6 =D
0/15 letters found
Clue 3
Skip counting
Skip count the footprint stamps along the dirt path to decode the clue message.
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
80
30
18
12
25
26
42
60
14
21
30
8
14
70
A
80
65
8
25
21
42
8
14
100
8
A
80
10
A
80
26
A
80
24
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100A
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90C
Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12E
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14K
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75R
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16U
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18S
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30W
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35D
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27T
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, ___, 70, 80I
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48H
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, ___, 27, 30Y
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, ___, 20, 22O
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120N
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, ___, 35, 40L
0/16 letters found
Clue 4
Place value
Look at the tens and ones on the treehouse door lock to find the 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
67
71
24
23
24
T
67
24
37
T
67
64
14
24
76
85
46
47
23
43
96
85
83
47
71
44
64
96
44
T
67
T
67
71
24
39
37
24
47
24
What number has 6 tens and 7 ones?T
What number has 7 tens and 1 one?H
What number has 6 tens and 4 ones?I
What number has 1 ten and 4 ones?V
What number has 3 tens and 7 ones?C
What number has 9 tens and 6 ones?R
What number has 7 tens and 6 ones?F
What number has 2 tens and 3 ones?D
What number has 8 tens and 3 ones?W
What number has 4 tens and 7 ones?N
What number has 3 tens and 9 ones?S
What number has 4 tens and 6 ones?U
What number has 8 tens and 5 ones?O
What number has 4 tens and 4 ones?A
What number has 4 tens and 3 ones?B
What number has 2 tens and 4 ones?E
0/16 letters found
Clue 5
Missing addends — the last clue
Find the missing number of campfire logs to reveal the final hint.
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
3 + ___ = 7
4 + ___ = 12
10 + ___ = 12
3 + ___ = 6
9 + ___ = 18
10 + ___ = 16
5 + ___ = 12
1 + ___ = 6
3 + ___ = 14
5 + ___ = 15
1 + ___ = 2
Step 2 — cross out the sentence with each answer
1.The villain read the secret map, then unlocked a box with a decoder ring.
2.The villain shined a flashlight around, then floated off with a glider cape.
3.The villain shined a flashlight around, then blew a loud whistle badge.
4.The villain scouted ahead with binoculars, then blew a loud whistle badge.
5.The villain swung in with a grappling hook, then put on night goggles.
6.The villain swung in with a grappling hook, then unlocked a box with a decoder ring.
7.The villain checked the magic compass, then blew a loud whistle badge.
8.The villain checked the magic compass, then put on night goggles.
9.The villain read the secret map, then floated off with a glider cape.
10.The villain read the secret map, then blew a loud whistle badge.
11.The villain checked the magic compass, then snuck away in tracker boots.
12.The villain scouted ahead with binoculars, then unlocked a box with a decoder ring.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Missing Golden Compass
Culprit: Ruby Rover (Binoculars · Decoder Ring · Left Handed · Brown Hair · Loud Whistles)
- Clue 1 (Addition): "THE SNEAK DOES NOT WEAR TRACKER BOOTS"12 + 5 = 17 (T) · 1 + 2 = 3 (B) · 6 + 14 = 20 (D) · 6 + 5 = 11 (O) · 7 + 7 = 14 (K) · 3 + 5 = 8 (S) · 12 + 6 = 18 (C) · 3 + 4 = 7 (W) · 4 + 2 = 6 (H) · 4 + 5 = 9 (R) · 9 + 4 = 13 (A) · 10 + 9 = 19 (N) · 7 + 5 = 12 (E)
- Clue 2 (Subtraction): "THE FOOTPRINTS SHOW A LEFT HANDED GRIP"19 - 5 = 14 (T) · 18 - 3 = 15 (S) · 12 - 1 = 11 (P) · 4 - 1 = 3 (G) · 20 - 4 = 16 (L) · 9 - 7 = 2 (H) · 14 - 7 = 7 (I) · 7 - 6 = 1 (W) · 20 - 1 = 19 (A) · 15 - 5 = 10 (F) · 20 - 2 = 18 (O) · 17 - 9 = 8 (N) · 20 - 3 = 17 (R) · 15 - 9 = 6 (E) · 19 - 6 = 13 (D)
- Clue 3 (Skip counting): "A LOUD WHISTLE SCARED THE SNEAK AWAY"Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (A) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90 = 70 (C) · Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12 = 8 (E) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (K) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (R) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16 = 12 (U) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (S) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (W) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35 = 25 (D) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27 = 21 (T) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, ___, 70, 80 = 60 (I) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48 = 42 (H) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, ___, 27, 30 = 24 (Y) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, ___, 20, 22 = 18 (O) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120 = 100 (N) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, ___, 35, 40 = 30 (L)
- Clue 4 (Place value): "THE DETECTIVE FOUND BROWN HAIR AT THE SCENE"What number has 6 tens and 7 ones? = 67 (T) · What number has 7 tens and 1 one? = 71 (H) · What number has 6 tens and 4 ones? = 64 (I) · What number has 1 ten and 4 ones? = 14 (V) · What number has 3 tens and 7 ones? = 37 (C) · What number has 9 tens and 6 ones? = 96 (R) · What number has 7 tens and 6 ones? = 76 (F) · What number has 2 tens and 3 ones? = 23 (D) · What number has 8 tens and 3 ones? = 83 (W) · What number has 4 tens and 7 ones? = 47 (N) · What number has 3 tens and 9 ones? = 39 (S) · What number has 4 tens and 6 ones? = 46 (U) · What number has 8 tens and 5 ones? = 85 (O) · What number has 4 tens and 4 ones? = 44 (A) · What number has 4 tens and 3 ones? = 43 (B) · What number has 2 tens and 4 ones? = 24 (E)
- Clue 5 (Missing addends): surviving statement (box 12) → Ruby Rover3 + ___ = 7 = 4 · 4 + ___ = 12 = 8 · 10 + ___ = 12 = 2 · 3 + ___ = 6 = 3 · 9 + ___ = 18 = 9 · 10 + ___ = 16 = 6 · 5 + ___ = 12 = 7 · 1 + ___ = 6 = 5 · 3 + ___ = 14 = 11 · 5 + ___ = 15 = 10 · 1 + ___ = 2 = 1
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Subtraction, Skip counting, Place value, Missing addends
- Reading level
- grades 1-2
- Theme
- The Mystery of the Missing Golden Compass — set in Whispering Woods Camp
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects