Count Storage under a Stated Encoding
Multiply the supplied character count by the stated bytes per character.
About 18 minutes, plus any extended practice
Open lesson 1Represent, Compress and Protect Information
Decode 3A2B. Compare keeping that record, sorting its expanded text and keeping only the A count. Explain why a public character code is not a security guarantee.
Before you begin
- Read character sequences and multiply whole numbers.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Decode a Run-Length Record
Expand each count-symbol pair in order, keeping separate runs separate.
About 18 minutes, plus any extended practice
Open lesson 2Identify Whether a Representation Loses Detail
Ask whether the complete original can be reconstructed from the trans formed record alone.
About 18 minutes, plus any extended practice
Open lesson 3Separate Encoding from Encryption
Distinguish a public representation convention, a keyed confidentiality mechanism, an access policy and an unsupported secrecy claim.
About 18 minutes, plus any extended practice
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.
Topic references
- 2026 CSTA PK–12 Computer Science Standards: topic reference — Data & Analysis; Systems & Security
These references informed the topic selection. They do not certify complete standards alignment.