Educational worksheet on time zones with a world map and related questions.

Let's solve the problem step by step using the Time Zone Map provided in your image.

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Understanding the Map

- The Earth is divided into 24 time zones, each about 15 degrees wide.
- Time zones are numbered 1 to 24, with Zone 1 being the International Date Line (IDL) at 180° longitude.
- As you move east from the IDL, the time increases by one hour per zone.
- The United States has six time zones.
- The map shows major cities and their corresponding time zones.

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Question 1: Through which oceans does the International Date Line pass?

The International Date Line runs roughly along the 180° longitude line.

Looking at the map:
- It passes through the Pacific Ocean.
- It also goes near or through some islands in the Pacific (like Fiji, Kiribati), but the main ocean it crosses is the Pacific Ocean.

✔ Answer: The International Date Line passes through the Pacific Ocean.

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Question 2: When it is 9:00 A.M. in Tokyo, what time is it in Rio de Janeiro?

#### Step 1: Find the time zones of Tokyo and Rio de Janeiro

From the map:

- Tokyo is in Time Zone 12 (or possibly 13 depending on exact position). But typically, Tokyo is in UTC+9, which corresponds to Zone 12 (since Zone 1 is 180°, and each zone is 15°).
- Rio de Janeiro is in Time Zone 4 (UTC-3).

But wait — let’s clarify how the zones are labeled.

The map shows:

- Zone 1 = 180° (IDL)
- Moving east, zones increase: 2, 3, ..., up to 24
- So Zone 12 is UTC+6 (because Zone 1 is 180°, and going east adds time)

Wait — this is a common confusion.

Actually, in this map, the zones are labeled such that:

- Zone 1 = 180° (IDL)
- Zone 2 = 165°E
- ...
- Zone 12 = 75°E → This would be around India/China
- Zone 13 = 60°E
- Zone 14 = 45°E
- ...
- Zone 24 = 15°W → Near Greenwich (UTC)

But actually, this map uses a different convention: it numbers the zones so that Zone 1 is the IDL, and moving east, the number increases.

So:
- Zone 1 = 180° (IDL)
- Zone 2 = 165°E
- ...
- Zone 12 = 75°E → Tokyo is around 139°E → That would be Zone 14?

Wait — let’s look carefully.

Looking at the map:

- Tokyo is in Zone 12
- Rio de Janeiro is in Zone 5

Now, since Zone 1 is the IDL, and we go eastward increasing the number, then:

- Zone 12 is 11 hours ahead of Zone 1
- Zone 5 is 4 hours ahead of Zone 1

But this doesn't make sense because Tokyo is ahead of Rio.

Wait — actually, if Zone 1 is the IDL, and Zone 24 is UTC (Greenwich), then:

- Zone 1 = 180° (IDL)
- Zone 2 = 165°E
- ...
- Zone 12 = 75°E
- Zone 13 = 60°E
- ...
- Zone 24 = 15°W → This is near UTC

But Tokyo is at 139°E, so it should be about 139 / 15 ≈ 9.27, so around UTC+9.

So if Zone 1 is 180°, then:

- Each zone is 15° → So moving west from 180° (Zone 1), we get:
- Zone 2 = 165°E
- Zone 3 = 150°E
- ...
- Zone 10 = 90°E
- Zone 11 = 75°E
- Zone 12 = 60°E → Not Tokyo!

This suggests the labeling might be opposite.

Wait — perhaps Zone 1 is 180°, and Zone 24 is 0° (Greenwich).

Then:

- Zone 1 = 180° (IDL)
- Zone 2 = 165°E
- ...
- Zone 13 = 15°E
- Zone 14 = 0° (Greenwich) → UTC
- Zone 15 = 15°W
- ...
- Zone 24 = 165°W

But Tokyo is at 139°E, which is 139°E, so from 180°, that’s 41° west, so 41 / 15 ≈ 2.73 → So Zone 3 or 4?

Wait — let’s try a better approach.

Look at the map legend:

It says:

> "Time Zones" are numbered 1 to 24, with Zone 1 = International Date Line (180°)

And as you go east, the number increases.

So:

- Zone 1 = 180° (IDL)
- Zone 2 = 165°E
- Zone 3 = 150°E
- Zone 4 = 135°E
- Zone 5 = 120°E
- Zone 6 = 105°E
- Zone 7 = 90°E
- Zone 8 = 75°E
- Zone 9 = 60°E
- Zone 10 = 45°E
- Zone 11 = 30°E
- Zone 12 = 15°E
- Zone 13 = 0° (Greenwich)
- Zone 14 = 15°W
- ...
- Zone 24 = 165°W

But Tokyo is at 139°E, so between 135°E (Zone 4) and 150°E (Zone 3) → closer to 135°E.

But 139°E is 4° east of 135°E, so still in Zone 4?

Wait — 135°E is Zone 4, so 139°E is within Zone 4?

But that can’t be — Tokyo is UTC+9, so it should be 9 hours ahead of UTC.

UTC is Zone 13 (0°), so Zone 4 is 13 - 4 = 9 hours ahead → Yes! That works.

So:

- Zone 4 = 135°E → UTC+9 → Tokyo
- Rio de Janeiro is at about 43°W, so 43° west of Greenwich, so UTC-3.

Where is UTC-3?

UTC is Zone 13, so UTC-3 is Zone 13 + 3 = Zone 16?

Wait — if Zone 13 = UTC, then:

- Zone 14 = UTC-1
- Zone 15 = UTC-2
- Zone 16 = UTC-3 → Rio de Janeiro

Yes.

So:

- Tokyo = Zone 4
- Rio de Janeiro = Zone 16

Now, time difference:

- From Zone 4 to Zone 16, how many zones apart?

But we have to go around the globe.

Since Zone 1 is IDL, and zones go from 1 to 24, the difference between two zones is:

|Zone A - Zone B|

But we must consider which direction.

- Tokyo = Zone 4
- Rio = Zone 16

Difference: |16 - 4| = 12 zones

But is Rio ahead or behind?

- Moving east, time increases.
- Zone 4 is farther east than Zone 16?
- Zone 1 = 180°
- Zone 4 = 135°E
- Zone 16 = ? Let's find it.

If Zone 1 = 180°
Zone 2 = 165°E
...
Zone 13 = 0°
Zone 14 = 15°W
Zone 15 = 30°W
Zone 16 = 45°W → Rio de Janeiro is at ~43°W → yes, Zone 16

So:

- Tokyo: 135°E → Zone 4
- Rio: 45°W → Zone 16

So from Zone 4 to Zone 16, going west, you cross:

- Zone 5 → 120°E
- ...
- Zone 13 → 0°
- Zone 14 → 15°W
- Zone 15 → 30°W
- Zone 16 → 45°W

So Zone 16 is 12 zones west of Zone 4

Each zone is 1 hour → 12 hours behind

So when it is 9:00 A.M. in Tokyo (Zone 4), it is 9:00 A.M. - 12 hours = 9:00 P.M. the previous day in Rio de Janeiro

But wait — Rio is west of Tokyo, so time is earlier.

So Rio is 12 hours behind Tokyo.

Therefore:

- 9:00 A.M. in Tokyo → 9:00 P.M. the previous day in Rio

But let’s check: Tokyo is UTC+9, Rio is UTC-3 → Difference = 9 - (-3) = 12 hours

Yes.

So:

✔ Answer: When it is 9:00 A.M. in Tokyo, it is 9:00 P.M. the previous day in Rio de Janeiro.

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Question 3: When it is 4:00 A.M. in Portland, what time is it in Sydney?

First, find the time zones.

From the map:

- Portland is in the Pacific Time Zone, which is Zone 8 (on the map)
- Sydney is in Zone 12

Wait — let’s confirm.

On the map:

- Portland is in Zone 8
- Sydney is in Zone 12

Now, Zone 1 is IDL, and zones increase eastward.

So:

- Zone 8 → 180° - (8-1)*15° = 180° - 105° = 75°W → That’s not right.

Wait — better way:

If Zone 1 = 180°
Then:
- Zone 2 = 165°E
- Zone 3 = 150°E
- ...
- Zone 8 = 180° - (8-1)*15° = 180° - 105° = 75°W → That’s east of 180°, no.

Wait — actually, if we go east from 180°, we decrease longitude.

Standard: 180° → 165°E → 150°E → ... → 0° → 15°W → ...

So:

- Zone 1: 180°
- Zone 2: 165°E
- Zone 3: 150°E
- Zone 4: 135°E
- Zone 5: 120°E
- Zone 6: 105°E
- Zone 7: 90°E
- Zone 8: 75°E → That’s India, not Portland.

But Portland is in western U.S., at about 123°W

So 123°W → How many zones?

From 180° to 123°W is:

- 180° to 123°W = 57° → 57 / 15 = 3.8 → So about Zone 4 or 5?

Wait — if Zone 1 = 180°
Then going west, we go to lower numbers? No.

Wait — the map says: as you move east, the time zone number increases

So:

- Zone 1 = 180°
- Zone 2 = 165°E
- ...
- Zone 13 = 0°
- Zone 14 = 15°W
- Zone 15 = 30°W
- Zone 16 = 45°W
- Zone 17 = 60°W
- Zone 18 = 75°W
- Zone 19 = 90°W
- Zone 20 = 105°W
- Zone 21 = 120°W
- Zone 22 = 135°W
- Zone 23 = 150°W
- Zone 24 = 165°W

Ah! So:

- Portland is at ~123°W → between 120°W and 135°W → Zone 21

Similarly:

- Sydney is at ~151°E → 150°E is Zone 3, 165°E is Zone 2 → so 151°E is Zone 3?

Wait — 150°E = Zone 3
135°E = Zone 4
120°E = Zone 5
So 151°E is Zone 3

But Sydney is at 151°E, so Zone 3

Now:

- Portland = Zone 21
- Sydney = Zone 3

Now, time difference:

- Zone 21 to Zone 3: going east from 21 to 3 → but 3 is after 21 in numbering? No.

Wait — the zones go from 1 to 24, with Zone 1 = 180°, and Zone 24 = 165°W

So:

- Zone 21 = 120°W
- Zone 22 = 135°W
- Zone 23 = 150°W
- Zone 24 = 165°W
- Zone 1 = 180°
- Zone 2 = 165°E
- Zone 3 = 150°E
- Zone 4 = 135°E
- etc.

So Zone 3 = 150°E

Sydney is at 151°E, so Zone 3

Portland is at 123°W → between 120°W and 135°W → Zone 21

Now, time difference:

- Zone 21 = 120°W
- Zone 3 = 150°E

How many zones apart?

We can go from Zone 21 to Zone 1 (IDL) = 21 zones
Then from Zone 1 to Zone 3 = 2 zones
Total = 21 + 2 = 23 zones? No.

Better: total zones = 24

- Difference = |3 - 21| = 18 zones

But which way?

- Zone 3 is east of Zone 21
- So time in Zone 3 is ahead of Zone 21

So Sydney is 18 hours ahead of Portland

Wait — let’s calculate actual time zones:

- Portland: 123°W → UTC-8 (PDT)
- Sydney: 151°E → UTC+10

So difference: 10 - (-8) = 18 hours

Yes!

So when it is 4:00 A.M. in Portland, it is 4:00 A.M. + 18 hours = 10:00 P.M. the same day in Sydney.

But wait — 4 A.M. + 18 hours = 10:00 P.M. the same day

✔ Answer: When it is 4:00 A.M. in Portland, it is 10:00 P.M. in Sydney.

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Question 4: What does this difference in time suggest about the location of the two cities?

The large time difference (18 hours) means that Portland and Sydney are on opposite sides of the Earth.

- They are separated by almost half the globe.
- One is in the Western Hemisphere (North America), and the other is in the Eastern Hemisphere (Australia).
- The time difference reflects their longitudinal separation — they are nearly 180° apart.

✔ Answer: The large time difference suggests that the two cities are located on opposite sides of the Earth, separated by a large longitudinal distance, which causes them to be in very different time zones.

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Activity: Write a story about going backward or forward in time. To what time period would you go? Include a drawing of your time machine.

*(This is creative writing — here's an example answer.)*

Story:

I built a time machine out of recycled parts and a powerful solar battery. It looks like a silver dome with glowing blue lights and a control panel full of buttons. I named it "ChronoPod."

One day, I decided to travel back to the year 1920 to see the early days of aviation. I set the dials to 1920 and pressed the button.

Whoosh!

I landed in a small field near Paris. Airships floated above, and people wore hats and long coats. I saw a biplane take off, its engine roaring. I met a young pilot who dreamed of flying across the Atlantic.

I learned that life was slower, but full of wonder. People were excited about new inventions, even though they didn’t have smartphones or computers.

After a week, I returned to my own time. I brought back a photo of the plane and shared my adventure with my friends.

*(Drawing description: A sleek silver pod with circular windows, propellers on top, and a glowing dial in the center. Wires and gears stick out from the back.)*

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✔ Final Answers:

1. The International Date Line passes through the Pacific Ocean.

2. When it is 9:00 A.M. in Tokyo, it is 9:00 P.M. the previous day in Rio de Janeiro.

3. When it is 4:00 A.M. in Portland, it is 10:00 P.M. in Sydney.

4. The large time difference suggests the cities are on opposite sides of the Earth, far apart in longitude.

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Let me know if you'd like a printable version or help with the drawing!