A video file has a size of 4,500 kilobytes. An online platform requires video files to be uploaded in megabytes....

1. TRANSLATE the problem information

• Given information:
  • Video file size: 4,500 kilobytes
  • Conversion factor: 1 megabyte = 1,000 kilobytes
  • Need to find: size in megabytes

2. INFER the conversion strategy

• Since we're converting from a smaller unit (kilobytes) to a larger unit (megabytes), we need to divide by the conversion factor
• Think of it this way: if 1,000 kilobytes makes 1 megabyte, then 4,500 kilobytes will make fewer megabytes

3. SIMPLIFY the calculation

• Set up the division: \(4{,}500 \div 1{,}000\)
• This equals 4.5

Answer: B (4.5)

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak INFER skill: Students confuse the direction of conversion and multiply instead of divide

They think: "I'm converting units, so I multiply by the conversion factor: \(4{,}500 \times 1{,}000 = 4{,}500{,}000\)"

This leads them to select Choice D (4,500,000)

Second Most Common Error:

Poor TRANSLATE reasoning: Students misread which unit they're converting to or from

They might think they need to convert megabytes to kilobytes instead of the reverse, leading to confusion about whether to multiply or divide.

This causes them to get stuck and guess randomly among the choices.

The Bottom Line:

Unit conversion problems require clear thinking about the relationship between units. When going from smaller to larger units, the number gets smaller (divide). When going from larger to smaller units, the number gets bigger (multiply).