🚀 SpaceGrade 4Reading: grades 3-4MultiplicationFractions of a numberWord problemsBar models
The Case of the Missing Star Compass
The Golden Star Compass has vanished from the main observatory. This special map guide is the only way to navigate the dark asteroid belt. Chief Astronomer Orion needs the Galaxy Patrol to track down the thief before they escape into deep space!
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 | Primary Thruster | Secondary Tech | Dominant Hand | Visor Color | Sensor Glitch |
|---|---|---|---|---|---|
| Guy Bluford | asteroid mining | plasma blasting | right-handed | blue visor | solar wind |
| Yuri Gagarin | solar charging | nebula hiding | right-handed | blue visor | ice crystals |
| Buzz Aldrin | rocket boosting | comet chasing | left-handed | silver visor | ice crystals |
| Ellen Ochoa | rocket boosting | radar jamming | right-handed | silver visor | cosmic dust |
| Al Worden | laser steering | radar jamming | left-handed | gold visor | ice crystals |
| Scott Kelly | laser steering | nebula hiding | left-handed | silver visor | ice crystals |
| Harrison Schmitt | gravity warping | nebula hiding | left-handed | silver visor | cosmic dust |
| Chris Hadfield | solar charging | comet chasing | left-handed | silver visor | ice crystals |
| Alan Shepard | laser steering | comet chasing | left-handed | silver visor | ice crystals |
| Jim Lovell | asteroid mining | nebula hiding | right-handed | silver visor | cosmic dust |
| Neil Armstrong | gravity warping | radar jamming | right-handed | gold visor | cosmic dust |
| Kalpana Chawla | gravity warping | plasma blasting | left-handed | blue visor | ice crystals |
| Mark Kelly | laser steering | radar jamming | right-handed | silver visor | ice crystals |
| Katherine Johnson | asteroid mining | shield building | left-handed | silver visor | ice crystals |
| Valentina Tereshkova | gravity warping | shield building | left-handed | blue visor | cosmic dust |
| Pete Conrad | gravity warping | shield building | right-handed | gold visor | ice crystals |
| Ed White | asteroid mining | nebula hiding | left-handed | blue visor | ice crystals |
| Gene Cernan | rocket boosting | comet chasing | left-handed | silver visor | solar wind |
| Peggy Whitson | solar charging | shield building | right-handed | blue visor | cosmic dust |
| John Glenn | asteroid mining | radar jamming | left-handed | blue visor | solar wind |
| Michael Collins | laser steering | nebula hiding | right-handed | blue visor | cosmic dust |
Clue 1
Multiplication facts (1-12)
The space station hangar has neat rows of starships. We count the booster engines by multiplying the rows to find a hidden log.
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
81
30
63
121
77
77
3
121
66
99
55
30
144
66
55
T
4
9
144
30
66
30
28
9
77
3
81
121
99
121
66
44
4 × 1 =T
11 × 11 =I
7 × 9 =V
5 × 11 =O
9 × 11 =D
11 × 7 =L
4 × 7 =B
10 × 3 =E
3 × 3 =U
3 × 1 =A
9 × 9 =H
6 × 11 =N
11 × 4 =G
12 × 12 =S
0/14 letters found
Clue 2
Fractions of a number
The crew divides a large box of space rations into equal fractional shares to see how much energy the intruder stole.
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
23
32
20
6
18
6
11
20
14
T
23
7
4
3
T
23
20
T
23
32
20
14
3
21
20
7
36
T
23
32
40
20
12
T
23
32
35
2
21
1/3 of 69 =T
8/10 of 40 =H
4/8 of 8 =R
4/8 of 70 =A
1/2 of 36 =U
2/5 of 30 =F
2/5 of 100 =L
2/3 of 30 =E
1/4 of 44 =P
7/10 of 10 =W
1/10 of 140 =C
1/2 of 12 =S
3/5 of 35 =D
6/8 of 4 =O
1/5 of 10 =N
2/6 of 108 =I
0/16 letters found
Clue 3
Word problems
An alien computer asks us to solve a word problem about rocket fuel cargo before it will unlock the security camera footage.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
I
32
31
48
31
77
19
12
27
A
L
12
Commander Leo found 26 oxygen tank yesterday and 6 more today. How many oxygen tank in all?I
Commander Leo found 9 space battery yesterday and 10 more today. How many space battery in all?Y
There were 48 star map. 17 were used up. How many star map are left?C
Commander Leo lined up 3 rows of 9 star map. How many star map in all?T
Commander Leo found 5 oxygen tank yesterday and 7 more today. How many oxygen tank in all?S
Commander Leo lined up 11 rows of 7 oxygen tank. How many oxygen tank in all?R
Commander Leo lined up 8 rows of 6 astro tool. How many astro tool in all?E
0/7 letters found
Clue 4
Bar model word problems
We draw a bar model to compare the weight of moon rocks brought back by different team members to trace the thief.
Draw a bar model to solve each word problem. Its answer reveals a letter — write the letters in the boxes to fill in the missing word.
Astrandofhairturnedupatthescene.
S
7
86
105
68
66
43
68
86
S
7
97
43
Commander Leo shares 77 star map equally among 11 teams. How many star map does each team get?
draw a bar model
Answer:→S
Commander Leo shares 194 space battery equally among 2 teams. How many space battery does each team get?
draw a bar model
Answer:→O
Commander Leo has 11 times as many space battery as a teammate. The teammate has 6 space battery. How many space battery does Commander Leo have?
draw a bar model
Answer:→E
Commander Leo has 215 space battery, packed 5 to a bag. How many bags can be filled?
draw a bar model
Answer:→R
Commander Leo used 1/2 of the astro tool on the first day. The other 34 astro tool were used the next day. How many astro tool were there in all?
draw a bar model
Answer:→V
The red team has 141 astro tool and the blue team has 36 astro tool. How many more astro tool does the red team have?
draw a bar model
Answer:→L
Commander Leo has 172 astro tool, packed 2 to a bag. How many bags can be filled?
draw a bar model
Answer:→I
0/7 letters found
Clue 5
Fractions of a number — the last clue
The navigation computer needs us to calculate a fraction of the remaining solar energy cells to reveal the final escape path.
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
2/5 of 30 = ?
2/8 of 4 = ?
2/3 of 9 = ?
1/5 of 20 = ?
4/8 of 6 = ?
1/4 of 44 = ?
5/10 of 20 = ?
2/3 of 12 = ?
5/10 of 10 = ?
3/6 of 14 = ?
3/5 of 15 = ?
Step 2 — cross out the sentence with each answer
1.The villain mined a rare space asteroid, then built a glowing force field.
2.The villain steered a heavy laser beam, then chased a wild green comet.
3.The villain warped local gravity fields, then jammed the space radar signals.
4.The villain boosted a massive rocket engine, then hid inside a dark nebula.
5.The villain warped local gravity fields, then built a glowing force field.
6.The villain boosted a massive rocket engine, then chased a wild green comet.
7.The villain charged solar power panels, then built a glowing force field.
8.The villain mined a rare space asteroid, then blasted hot plasma streams.
9.The villain charged solar power panels, then jammed the space radar signals.
10.The villain warped local gravity fields, then blasted hot plasma streams.
11.The villain warped local gravity fields, then hid inside a dark nebula.
12.The villain charged solar power panels, then chased a wild green comet.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Case of the Missing Star Compass
Culprit: Alan Shepard (laser steering · comet chasing · left-handed · silver visor · ice crystals)
- Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DOES NOT USE NEBULA HIDING"4 × 1 = 4 (T) · 11 × 11 = 121 (I) · 7 × 9 = 63 (V) · 5 × 11 = 55 (O) · 9 × 11 = 99 (D) · 11 × 7 = 77 (L) · 4 × 7 = 28 (B) · 10 × 3 = 30 (E) · 3 × 3 = 9 (U) · 3 × 1 = 3 (A) · 9 × 9 = 81 (H) · 6 × 11 = 66 (N) · 11 × 4 = 44 (G) · 12 × 12 = 144 (S)
- Clue 2 (Fractions of a number): "THE SUSPECT WROTE THE CODE WITH LEFT HAND"1/3 of 69 = 23 (T) · 8/10 of 40 = 32 (H) · 4/8 of 8 = 4 (R) · 4/8 of 70 = 35 (A) · 1/2 of 36 = 18 (U) · 2/5 of 30 = 12 (F) · 2/5 of 100 = 40 (L) · 2/3 of 30 = 20 (E) · 1/4 of 44 = 11 (P) · 7/10 of 10 = 7 (W) · 1/10 of 140 = 14 (C) · 1/2 of 12 = 6 (S) · 3/5 of 35 = 21 (D) · 6/8 of 4 = 3 (O) · 1/5 of 10 = 2 (N) · 2/6 of 108 = 36 (I)
- Clue 3 (Word problems): "ICE CRYSTALS"Commander Leo found 26 oxygen tank yesterday and 6 more today. How many oxygen tank in all? = 32 (I) · Commander Leo found 9 space battery yesterday and 10 more today. How many space battery in all? = 19 (Y) · There were 48 star map. 17 were used up. How many star map are left? = 31 (C) · Commander Leo lined up 3 rows of 9 star map. How many star map in all? = 27 (T) · Commander Leo found 5 oxygen tank yesterday and 7 more today. How many oxygen tank in all? = 12 (S) · Commander Leo lined up 11 rows of 7 oxygen tank. How many oxygen tank in all? = 77 (R) · Commander Leo lined up 8 rows of 6 astro tool. How many astro tool in all? = 48 (E)
- Clue 4 (Bar model word problems): "SILVER VISOR"Commander Leo shares 77 star map equally among 11 teams. How many star map does each team get? = 7 (S) · Commander Leo shares 194 space battery equally among 2 teams. How many space battery does each team get? = 97 (O) · Commander Leo has 11 times as many space battery as a teammate. The teammate has 6 space battery. How many space battery does Commander Leo have? = 66 (E) · Commander Leo has 215 space battery, packed 5 to a bag. How many bags can be filled? = 43 (R) · Commander Leo used 1/2 of the astro tool on the first day. The other 34 astro tool were used the next day. How many astro tool were there in all? = 68 (V) · The red team has 141 astro tool and the blue team has 36 astro tool. How many more astro tool does the red team have? = 105 (L) · Commander Leo has 172 astro tool, packed 2 to a bag. How many bags can be filled? = 86 (I)
- Clue 5 (Fractions of a number): surviving statement (box 2) → Alan Shepard2/5 of 30 = 12 · 2/8 of 4 = 1 · 2/3 of 9 = 6 · 1/5 of 20 = 4 · 4/8 of 6 = 3 · 1/4 of 44 = 11 · 5/10 of 20 = 10 · 2/3 of 12 = 8 · 5/10 of 10 = 5 · 3/6 of 14 = 7 · 3/5 of 15 = 9
About this mystery
- Grade level
- Grade 4 math
- Math topics
- Multiplication, Fractions of a number, Word problems, Bar models
- Reading level
- grades 3-4
- Theme
- The Case of the Missing Star Compass — set in Lunar Outpost Alpha
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects