# data[].attributes.body
Using ancient Chinese Tangram, following the instructions to recreate pictures

# data[].attributes.attachment_link.readable_text
Here you can explore our interactive tangrams.

Can you create the blue shape on the right using the seven trangram pieces on the left?

Each blue shape features in one of our World of Tan stories, which relate to Granma T who owns a removals business in China.
How to use the interactivity:
You can select a particular tangram to complete using the arrows above the 'Change tangram' text.

If you click the image of the two small squares immediately to the bottom left of the blue shape , you will see that the blue shape slides to the left, underneath the tangram pieces, allowing you to arrange the pieces directly on top of the blue picture.

You can select a tangram piece by clicking on it. The piece which is currently selected is shown above the word 'Selection'.

You can move a tangram piece by dragging it, or by selecting it and then using the arrow keys above the word 'Move'.

A tangram piece can be rotated by selecting it and then clicking on either of the 'Rotate' buttons.

# data[].attributes.attachment_link.description
Here you can explore our interactive tangrams.

# data[].attributes.body
小明 takes the Shanghai Metro Line 2 from Hongqiao Airport to People's Square. If the train travels at an average speed of 80 km/h and the distance is 16 kilometers, how long will the journey take? For an extra challenge, if his train card has ¥45, how many more similar trips can he make if each trip costs ¥5?

# data[].attributes.body
The Oriental Pearl Tower has a spherical observation deck at 263 meters high. If the deck has a diameter of 45 meters, what is the approximate surface area of the observation deck? (Use π = 3.14)

# data[].attributes.body
A street vendor sells baozi at ¥3 each or ¥30 for a dozen. If your class of 28 students wants to buy baozi and spend the least amount of money possible, how should they purchase the baozi to ensure everyone gets one? How much money will they save compared to buying them individually?

# data[].attributes.body
In Chinese culture, 8 is considered lucky. If you start with the number 8 and multiply it by itself, then take the last two digits of each answer and multiply again, what pattern do you notice? Try this 5 times!

8 × 8 = 64
64 × 64 = 4096
96 × 96 = ?
Continue the pattern!

# data[].attributes.body
Create equivalent fractions:
3/4 = ?/12 = ?/24
Then explain why these would be useful when dividing mooncakes equally among different numbers of people!

# data[].attributes.body
Explore these interactive geometry activities perfect for Grade 4 students. Practice with shapes, angles, and transformations in this engaging online tool.

# data[].attributes.attachment_link.description
Explore over 300 resources through which elementary school students can learn math concepts in a fun and interactive way!

# data[].attributes.body
Access free math lessons in Chinese and English. Perfect for bilingual learners! Focus on topics like fractions, decimals, and geometry with clear explanations and lots of practice problems.

# data[].attributes.attachment_link.readable_text
If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

To log in and use all the features of Khan Academy, please enable JavaScript in your browser.

15,400 possible mastery points

# data[].attributes.attachment_link.description
Learn fourth grade math-arithmetic, measurement, geometry, fractions, and more. This course is aligned with Common Core standards.

# data[].attributes.body
Create math problems using Mahjong tiles! If bamboo tiles represent ones and dot tiles represent tens, create three 3-digit numbers that sum to exactly 1000. How many different combinations can you find?

# data[].attributes.body
Using the ancient Chinese puzzle Tangram, create these shapes and calculate their areas:
1. A square using all 7 pieces
2. A triangle using 5 pieces
3. A rectangle using 6 pieces
Bonus: Calculate the perimeter of each shape!

# data[].attributes.attachment_link.title
IXL | Multiply two fractions | 5th grade math

# data[].attributes.attachment_link.description
Improve your math knowledge with free questions in "Multiply two fractions" and thousands of other math skills.

# data[].attributes.attachment_link.title
IXL | What decimal number is illustrated? | 5th grade math

# data[].attributes.attachment_link.description
Improve your math knowledge with free questions in "What decimal number is illustrated?" and thousands of other math skills.

# data[].attributes.attachment_link.title
IXL | Model decimals and fractions | 5th grade math

# data[].attributes.attachment_link.description
Improve your math knowledge with free questions in “Model decimals and fractions” and thousands of other math skills.

# data[].attributes.attachment_link.title
IXL | Multiply a decimal by a power of ten: with exponents | 5th grade math

# data[].attributes.attachment_link.description
Improve your math knowledge with free questions in “Multiply a decimal by a power of ten: with exponents” and thousands of other math skills.