🚀 SpaceGrade 1Reading: grades 3-4Place valueAdditionSubtractionSkip countingMissing addends
The Case of the Missing Moon Crystal
Someone snuck into the Lunar Research Dome and swapped the glowing moon crystal with a fake space pebble! Detective, check the logs and decode the clues to catch the cosmic culprit.
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 Gadget | Bonus Tool | Goggles | Spacedo | Weakness |
|---|---|---|---|---|---|
| Sally Ride | gravity ray | meteor blaster | no space goggles | floating zero g ponytail | bright strobe flash |
| Jessica Meir | rocket boots | meteor blaster | no space goggles | bright neon buzzcut | bright strobe flash |
| Sunita Williams | warp drive | starlight cloak | no space goggles | silver helmet hair | bright strobe flash |
| Michael Collins | laser cutter | solar scanner | wears space goggles | floating zero g ponytail | sticky moon foam |
| Scott Kelly | laser cutter | solar scanner | no space goggles | bright neon buzzcut | sticky moon foam |
| Chris Hadfield | plasma shield | starlight cloak | no space goggles | silver helmet hair | loud alarm horn |
| Guion Bluford | warp drive | starlight cloak | no space goggles | bright neon buzzcut | loud alarm horn |
| Neil Armstrong | warp drive | meteor blaster | wears space goggles | silver helmet hair | bright strobe flash |
| Victor Glover | laser cutter | solar scanner | wears space goggles | floating zero g ponytail | bright strobe flash |
| Ellen Ochoa | rocket boots | meteor blaster | wears space goggles | floating zero g ponytail | bright strobe flash |
| Mark Kelly | laser cutter | solar scanner | no space goggles | silver helmet hair | bright strobe flash |
| Kalpana Chawla | rocket boots | comet thruster | wears space goggles | floating zero g ponytail | bright strobe flash |
| Alan Shepard | gravity ray | solar scanner | wears space goggles | floating zero g ponytail | loud alarm horn |
| Bernard Harris | plasma shield | solar scanner | wears space goggles | floating zero g ponytail | bright strobe flash |
| Samantha Cristoforetti | plasma shield | astro magnet | no space goggles | bright neon buzzcut | loud alarm horn |
| Peggy Whitson | plasma shield | solar scanner | wears space goggles | silver helmet hair | sticky moon foam |
| Leland Melvin | rocket boots | meteor blaster | no space goggles | silver helmet hair | loud alarm horn |
| Eileen Collins | warp drive | comet thruster | no space goggles | silver helmet hair | sticky moon foam |
| Yuri Gagarin | gravity ray | starlight cloak | no space goggles | bright neon buzzcut | sticky moon foam |
| Christina Koch | gravity ray | astro magnet | wears space goggles | floating zero g ponytail | bright strobe flash |
| Valentina Tereshkova | plasma shield | astro magnet | wears space goggles | floating zero g ponytail | bright strobe flash |
Clue 1
Place value
The station main computer sorted the vault code digits by tens and ones to unlock the first secure file.
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
55
20
35
58
92
64
64
32
92
52
91
92
91
52
39
T
55
63
74
35
32
52
32
74
T
55
84
39
27
32
18
52
35
T
55
What number has 5 tens and 5 ones?T
What number has 1 ten and 8 ones?G
What number has 9 tens and 1 one?D
What number has 3 tens and 2 ones?A
What number has 5 tens and 2 ones?N
What number has 3 tens and 9 ones?O
What number has 2 tens and 0 ones?H
What number has 2 tens and 7 ones?M
What number has 6 tens and 3 ones?U
What number has 7 tens and 4 ones?S
What number has 9 tens and 2 ones?I
What number has 3 tens and 5 ones?E
What number has 8 tens and 4 ones?R
What number has 5 tens and 8 ones?V
What number has 6 tens and 4 ones?L
0/15 letters found
Clue 2
Addition
Commander Vance added up the total energy canisters stored in the airlock bays.
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
7
19
14
8
16
17
10
10
10
A
7
19
5
13
3
19
14
16
5
10
11
A
7
4
17
5
3
5
5
13
17
10
4 + 3 =A
1 + 2 =O
6 + 2 =T
4 + 9 =L
14 + 5 =W
6 + 10 =N
2 + 2 =C
5 + 12 =E
6 + 4 =S
1 + 4 =G
7 + 4 =P
8 + 6 =I
0/12 letters found
Clue 3
Subtraction
The security droid subtracted the damaged solar panels from the total power deck.
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
4
9
11
2
1
12
18
10
7
1
7
11
10
12
13
18
15
2
9
T
4
7
T
4
18
5
13
11
16
8
12
7
9
9 - 5 =T
19 - 8 =E
13 - 6 =S
14 - 6 =L
10 - 8 =G
10 - 5 =O
15 - 2 =B
11 - 2 =H
20 - 2 =R
20 - 4 =F
16 - 1 =I
16 - 6 =D
20 - 8 =A
9 - 8 =U
0/14 letters found
Clue 4
Skip counting
Cadet Leo counted the supply crates lined up in equal rows across the launch pad.
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
60
14
80
39
80
30
39
27
10
39
130
27
T
60
T
60
80
120
42
35
65
27
42
T
60
100
30
16
15
80
10
27
16
130
27
30
12
T
60
42
100
65
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, ___, 70, 80T
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140D
Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18Y
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20G
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45S
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45F
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14R
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21Z
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48A
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150P
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120I
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18H
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33O
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75L
Skip-count by 10s. Fill the blank: 10, 20, ___, 40, 50N
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100E
0/16 letters found
Clue 5
Missing addends — the last clue
Officer Nova checked how many extra fuel cells were needed to fill the rocket tanks.
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
2 + ___ = 4
2 + ___ = 3
10 + ___ = 22
5 + ___ = 13
7 + ___ = 12
5 + ___ = 15
4 + ___ = 15
6 + ___ = 9
9 + ___ = 13
3 + ___ = 9
8 + ___ = 15
Step 2 — cross out the sentence with each answer
1.The villain flew over the guard rail, then shattered the hatch with a meteor blaster.
2.The villain sliced the solar wires, then checked the map with a solar scanner.
3.The villain blasted the vault lock, then checked the map with a solar scanner.
4.The villain blasted the vault lock, then snuck off under a starlight cloak.
5.The villain blocked the laser beam, then escaped fast using a comet thruster.
6.The villain blocked the laser beam, then shattered the hatch with a meteor blaster.
7.The villain warped past the security door, then escaped fast using a comet thruster.
8.The villain blasted the vault lock, then escaped fast using a comet thruster.
9.The villain flew over the guard rail, then escaped fast using a comet thruster.
10.The villain blocked the laser beam, then pulled the key with an astro magnet.
11.The villain warped past the security door, then pulled the key with an astro magnet.
12.The villain blocked the laser beam, then checked the map with a solar scanner.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Case of the Missing Moon Crystal
Culprit: Kalpana Chawla (rocket boots · comet thruster · wears space goggles · floating zero g ponytail · bright strobe flash)
- Clue 1 (Place value): "THE VILLAIN DID NOT USE AN ASTRO MAGNET"What number has 5 tens and 5 ones? = 55 (T) · What number has 1 ten and 8 ones? = 18 (G) · What number has 9 tens and 1 one? = 91 (D) · What number has 3 tens and 2 ones? = 32 (A) · What number has 5 tens and 2 ones? = 52 (N) · What number has 3 tens and 9 ones? = 39 (O) · What number has 2 tens and 0 ones? = 20 (H) · What number has 2 tens and 7 ones? = 27 (M) · What number has 6 tens and 3 ones? = 63 (U) · What number has 7 tens and 4 ones? = 74 (S) · What number has 9 tens and 2 ones? = 92 (I) · What number has 3 tens and 5 ones? = 35 (E) · What number has 8 tens and 4 ones? = 84 (R) · What number has 5 tens and 8 ones? = 58 (V) · What number has 6 tens and 4 ones? = 64 (L)
- Clue 2 (Addition): "A WITNESS SAW GLOWING SPACE GOGGLES"4 + 3 = 7 (A) · 1 + 2 = 3 (O) · 6 + 2 = 8 (T) · 4 + 9 = 13 (L) · 14 + 5 = 19 (W) · 6 + 10 = 16 (N) · 2 + 2 = 4 (C) · 5 + 12 = 17 (E) · 6 + 4 = 10 (S) · 1 + 4 = 5 (G) · 7 + 4 = 11 (P) · 8 + 6 = 14 (I)
- Clue 3 (Subtraction): "THE GUARDS USED A BRIGHT STROBE FLASH"9 - 5 = 4 (T) · 19 - 8 = 11 (E) · 13 - 6 = 7 (S) · 14 - 6 = 8 (L) · 10 - 8 = 2 (G) · 10 - 5 = 5 (O) · 15 - 2 = 13 (B) · 11 - 2 = 9 (H) · 20 - 2 = 18 (R) · 20 - 4 = 16 (F) · 16 - 1 = 15 (I) · 16 - 6 = 10 (D) · 20 - 8 = 12 (A) · 9 - 8 = 1 (U)
- Clue 4 (Skip counting): "THE SENSOR SPOTTED A FLOATING ZERO G PONYTAIL"Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, ___, 70, 80 = 60 (T) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (D) · Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18 = 12 (Y) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20 = 16 (G) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45 = 39 (S) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (F) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (R) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21 = 15 (Z) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48 = 42 (A) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150 = 130 (P) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120 = 100 (I) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (H) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33 = 27 (O) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (L) · Skip-count by 10s. Fill the blank: 10, 20, ___, 40, 50 = 30 (N) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (E)
- Clue 5 (Missing addends): surviving statement (box 9) → Kalpana Chawla2 + ___ = 4 = 2 · 2 + ___ = 3 = 1 · 10 + ___ = 22 = 12 · 5 + ___ = 13 = 8 · 7 + ___ = 12 = 5 · 5 + ___ = 15 = 10 · 4 + ___ = 15 = 11 · 6 + ___ = 9 = 3 · 9 + ___ = 13 = 4 · 3 + ___ = 9 = 6 · 8 + ___ = 15 = 7
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Place value, Addition, Subtraction, Skip counting, Missing addends
- Reading level
- grades 3-4
- Theme
- The Case of the Missing Moon Crystal — set in Starlight Lunar Outpost
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects