
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A report from the top 20 institutions pointed out that in the past decade, China has increased innovation investment in all aspects. Research and development (R&D) expenditure has continued to grow rapidly. In 2021, China's R&D expenditure reached 2800 billion yuan, ranking second in the world, second only to the United States. Express the number 28000 in scientific notation as ______.

Present the answer in LaTex format: \boxed{Your answer}
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