# Mixed Practice: Data Representation

- **Track:** Cambridge IGCSE™ Computer Science (0478 / 0984) (CAMBRIDGE IGCSE 0478)
- **Module:** Section 1: Data Representation
- **Estimated Duration:** 20 minutes
- **Access:** Open Theory + Free Practice

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## Theory & Conceptual Background

Close your notes and try the mixed questions. Write calculations or a diagram on paper where useful. If you miss an item, explain the misconception and revisit its lesson before trying again.

## Delayed review

Return to these questions after studying another module, rather than only repeating them immediately. Change a value or a condition and predict how the answer changes. Explain one answer aloud without relying on a memorised keyword.

## Written transfer

Choose a practical example from this module and explain the mechanism, one benefit and one limitation. Check that each point refers to the example. Structured automatic checks cannot judge the quality of this explanation; use the lesson's worked examples and a teacher's feedback for that.

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## Interactive Exercises & Autotest Specifications

### Exercise 1: Cumulative Check: Apply earlier ideas (Fill in blank, 30 XP)

**Instructions:**
Work out each answer before submitting. Denary value of binary 10010110: Hexadecimal for denary 4095: Binary for hexadecimal 0F (eight bits): Denary for hexadecimal F0: Bits for 30 bytes: Raw bytes for a 32 by 16 image at four bits/pixel:


**Starter Code:**
```text
{"prompt":"Cumulative Check: Apply earlier ideas","template":"1. Denary value of binary 10010110: [blank_1]\n2. Hexadecimal for denary 4095: [blank_2]\n3. Binary for hexadecimal 0F (eight bits): [blank_3]\n4. Denary for hexadecimal F0: [blank_4]\n5. Bits for 30 bytes: [blank_5]\n6. Raw bytes for a 32 by 16 image at four bits/pixel: [blank_6]","blanks":[{"id":"blank_1"},{"id":"blank_2"},{"id":"blank_3"},{"id":"blank_4"},{"id":"blank_5"},{"id":"blank_6"}],"word_bank":["150","FFF","00001111","240","256","140","FFE","FFFF","11110000","00001110","480","128"]}
```