Grade 1Reading: grades 1-2Place valueAdditionSubtractionSkip countingMissing addends
The Camp Cabin Mystery
Oh no! The Golden Compass is gone from the main cabin. Head Guide Barnaby needs our help. One of the campers took 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 | Explorer Gear | Camp Badge | Writing Style | Safari Hat | Big Fear |
|---|---|---|---|---|---|
| Rex | map compass | fire building badge | left-handed writer | red safari hat | scared of mud |
| Toby | climbing hook | bug catching badge | left-handed writer | blue safari hat | scared of spiders |
| Noah | rope lasso | knot tying badge | left-handed writer | red safari hat | scared of mud |
| Emma | rope lasso | knot tying badge | left-handed writer | red safari hat | scared of spiders |
| Ruby | climbing hook | fire building badge | left-handed writer | red safari hat | scared of mud |
| Ben | climbing hook | fire building badge | left-handed writer | red safari hat | scared of frogs |
| Luke | rope lasso | map reading badge | left-handed writer | red safari hat | scared of mud |
| Jack | walkie talkie | knot tying badge | right-handed writer | red safari hat | scared of mud |
| Max | walkie talkie | bug catching badge | right-handed writer | green safari hat | scared of spiders |
| Amy | climbing hook | tent pitching badge | right-handed writer | blue safari hat | scared of spiders |
| Abby | climbing hook | knot tying badge | left-handed writer | blue safari hat | scared of mud |
| Jake | map compass | bug catching badge | left-handed writer | red safari hat | scared of mud |
| Leo | bright flashlight | map reading badge | left-handed writer | green safari hat | scared of frogs |
| Finn | rope lasso | tent pitching badge | right-handed writer | blue safari hat | scared of spiders |
| Cody | climbing hook | fire building badge | left-handed writer | blue safari hat | scared of frogs |
| Lily | map compass | knot tying badge | right-handed writer | red safari hat | scared of spiders |
| Mia | walkie talkie | knot tying badge | left-handed writer | red safari hat | scared of spiders |
| Joy | rope lasso | fire building badge | right-handed writer | green safari hat | scared of mud |
| Zoe | rope lasso | knot tying badge | left-handed writer | blue safari hat | scared of mud |
| Eli | rope lasso | fire building badge | left-handed writer | red safari hat | scared of frogs |
| Ella | map compass | tent pitching badge | left-handed writer | blue safari hat | scared of frogs |
Clue 1
Place value
We find a digital lock box on the trail. It has tens and ones blocks on the screen. Let us count the blocks to open the box and get 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
69
28
74
22
60
74
51
18
71
44
51
89
91
74
24
28
51
22
60
26
89
51
91
24
74
51
70
95
60
78
33
51
70
78
74
What number has 6 tens and 9 ones?T
What number has 7 tens and 1 one?Y
What number has 7 tens and 0 ones?D
What number has 3 tens and 3 ones?B
What number has 9 tens and 5 ones?I
What number has 7 tens and 8 ones?G
What number has 7 tens and 4 ones?E
What number has 2 tens and 8 ones?H
What number has 5 tens and 1 one?A
What number has 8 tens and 9 ones?M
What number has 4 tens and 4 ones?C
What number has 2 tens and 4 ones?R
What number has 9 tens and 1 one?P
What number has 6 tens and 0 ones?N
What number has 2 tens and 2 ones?S
What number has 1 ten and 8 ones?K
What number has 2 tens and 6 ones?O
0/17 letters found
Clue 2
Addition
We find some footprints in the wet dirt. First we see four tracks. Then we see three more tracks. Let us add them up to find the next 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
6
2
5
14
15
5
20
4
16
11
20
3
7
5
18
12
18
13
T
6
5
14
12
13
T
6
2
T
6
2
5
13
18
10
5
19
T
6
2
20
15
9
1 + 5 =T
6 + 14 =A
14 + 5 =F
1 + 4 =E
6 + 12 =R
2 + 2 =K
2 + 5 =P
6 + 9 =N
8 + 5 =I
2 + 1 =M
3 + 7 =L
6 + 8 =S
8 + 8 =Y
5 + 6 =C
5 + 7 =W
1 + 1 =H
4 + 5 =D
0/17 letters found
Clue 3
Subtraction
We need energy to keep up the search. We start with eight sweet berries in our pack. We eat some berries. Let us subtract to see how many are left.
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
8
9
2
6
19
2
1
17
16
15
1
14
5
2
11
11
1
19
1
10
1
16
3
11
13
14
1
14
7
12
5
7
12
12
4
2
16 - 8 =T
10 - 1 =H
13 - 7 =S
20 - 1 =N
8 - 7 =A
13 - 1 =D
12 - 8 =L
17 - 1 =Y
9 - 4 =P
16 - 6 =W
4 - 2 =E
19 - 4 =C
9 - 2 =U
18 - 1 =K
20 - 7 =O
20 - 6 =M
11 - 8 =F
19 - 8 =R
0/18 letters found
Clue 4
Skip counting
We must climb up the big wood stairs to the treehouse. We count the steps by twos to go fast. Let us skip count to reach the top where a clue is hidden.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
W
6
26
20
35
140
80
70
39
60
24
50
12
15
10
24
26
70
18
10
24
39
36
35
80
10
15
26
60
24
39
80
42
15
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10W
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100N
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, ___, 21, 24S
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14T
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42P
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48C
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90D
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45A
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21H
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60I
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30E
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160U
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45O
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, ___, 22, 24F
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, ___, 65, 70B
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, ___, 26, 28R
Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18G
0/17 letters found
Clue 5
Missing addends — the last clue
Our team needs six dry sticks to build a campfire. We only have four sticks. Let us find out how many more we need to get the final clue.
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
10 + ___ = 16
5 + ___ = 13
1 + ___ = 6
10 + ___ = 20
8 + ___ = 19
8 + ___ = 20
6 + ___ = 8
8 + ___ = 9
5 + ___ = 8
1 + ___ = 10
6 + ___ = 13
Step 2 — cross out the sentence with each answer
1.The villain threw a long rope, then looked at the stars.
2.The villain shined a strong light, then set up a small tent.
3.The villain threw a long rope, then gathered dry sticks.
4.The villain followed a trail map, then swept for beetles.
5.The villain threw a long rope, then tied a double knot.
6.The villain followed a trail map, then gathered dry sticks.
7.The villain swung a climbing hook, then looked at the stars.
8.The villain swung a climbing hook, then gathered dry sticks.
9.The villain swung a climbing hook, then tied a double knot.
10.The villain followed a trail map, then set up a small tent.
11.The villain shined a strong light, then tied a double knot.
12.The villain called on a radio, then gathered dry sticks.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Camp Cabin Mystery
Culprit: Jake (map compass · bug catching badge · left-handed writer · red safari hat · scared of mud)
- Clue 1 (Place value): "THE SNEAKY CAMPER HAS NO MAP READING BADGE"What number has 6 tens and 9 ones? = 69 (T) · What number has 7 tens and 1 one? = 71 (Y) · What number has 7 tens and 0 ones? = 70 (D) · What number has 3 tens and 3 ones? = 33 (B) · What number has 9 tens and 5 ones? = 95 (I) · What number has 7 tens and 8 ones? = 78 (G) · What number has 7 tens and 4 ones? = 74 (E) · What number has 2 tens and 8 ones? = 28 (H) · What number has 5 tens and 1 one? = 51 (A) · What number has 8 tens and 9 ones? = 89 (M) · What number has 4 tens and 4 ones? = 44 (C) · What number has 2 tens and 4 ones? = 24 (R) · What number has 9 tens and 1 one? = 91 (P) · What number has 6 tens and 0 ones? = 60 (N) · What number has 2 tens and 2 ones? = 22 (S) · What number has 1 ten and 8 ones? = 18 (K) · What number has 2 tens and 6 ones? = 26 (O)
- Clue 2 (Addition): "THE SNEAKY CAMPER WRITES WITH THEIR LEFT HAND"1 + 5 = 6 (T) · 6 + 14 = 20 (A) · 14 + 5 = 19 (F) · 1 + 4 = 5 (E) · 6 + 12 = 18 (R) · 2 + 2 = 4 (K) · 2 + 5 = 7 (P) · 6 + 9 = 15 (N) · 8 + 5 = 13 (I) · 2 + 1 = 3 (M) · 3 + 7 = 10 (L) · 6 + 8 = 14 (S) · 8 + 8 = 16 (Y) · 5 + 6 = 11 (C) · 5 + 7 = 12 (W) · 1 + 1 = 2 (H) · 4 + 5 = 9 (D)
- Clue 3 (Subtraction): "THE SNEAKY CAMPER RAN AWAY FROM A MUD PUDDLE"16 - 8 = 8 (T) · 10 - 1 = 9 (H) · 13 - 7 = 6 (S) · 20 - 1 = 19 (N) · 8 - 7 = 1 (A) · 13 - 1 = 12 (D) · 12 - 8 = 4 (L) · 17 - 1 = 16 (Y) · 9 - 4 = 5 (P) · 16 - 6 = 10 (W) · 4 - 2 = 2 (E) · 19 - 4 = 15 (C) · 9 - 2 = 7 (U) · 18 - 1 = 17 (K) · 20 - 7 = 13 (O) · 20 - 6 = 14 (M) · 11 - 8 = 3 (F) · 19 - 8 = 11 (R)
- Clue 4 (Skip counting): "WE FOUND A BRIGHT RED STRAP ON THE BRANCH"Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (W) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (N) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, ___, 21, 24 = 18 (S) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (T) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (P) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48 = 42 (C) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90 = 70 (D) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45 = 39 (A) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21 = 15 (H) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60 = 50 (I) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (E) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160 = 140 (U) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (O) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, ___, 22, 24 = 20 (F) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, ___, 65, 70 = 60 (B) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, ___, 26, 28 = 24 (R) · Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18 = 12 (G)
- Clue 5 (Missing addends): surviving statement (box 4) → Jake10 + ___ = 16 = 6 · 5 + ___ = 13 = 8 · 1 + ___ = 6 = 5 · 10 + ___ = 20 = 10 · 8 + ___ = 19 = 11 · 8 + ___ = 20 = 12 · 6 + ___ = 8 = 2 · 8 + ___ = 9 = 1 · 5 + ___ = 8 = 3 · 1 + ___ = 10 = 9 · 6 + ___ = 13 = 7
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Place value, Addition, Subtraction, Skip counting, Missing addends
- Reading level
- grades 1-2
- Theme
- The Camp Cabin Mystery — set in Camp Wildwood Canopy
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects