Computer Science (Nepal SEE, Grade 10): Concepts, Conversions and Code
The Computer Science domain of the Nepal SEE tests the Grade 10 CDC syllabus at two levels: factual recall (definitions, device categories, ethics) and procedure (number-system conversion, QBASIC program traces, database and HTML construction). Marks arrive as very short (1 mark), short (2 marks) and long (4 marks) items, so a precise one-line definition and a clearly staged calculation are scored differently - show every step even when the answer is obvious.
Core rules and concepts
- Number systems: decimal, binary, octal and hexadecimal. To convert from decimal, divide repeatedly by the target base and read remainders bottom-up. To convert to decimal, expand positional weights. Octal and hexadecimal convert to binary in 3-bit and 4-bit groups; 1's complement inverts all bits, and 2's complement inverts then adds 1.
- QBASIC: sequential statements, IF...THEN...ELSE, FOR...NEXT, DO...LOOP, arrays declared with DIM, and modular code via SUB...END SUB (no return value) versus FUNCTION...END FUNCTION (returns one value).
- Database (MS Access): a table holds fields (columns) and records (rows); the primary key is unique and non-null; queries retrieve, forms accept input, reports print output.
- HTML: the page skeleton is html/head/title/body; know heading, paragraph, list, table, image and anchor tags with their attributes.
- Networking and ICT ethics: LAN versus WAN, topology, IP address, modem/router/switch, computer virus types and antivirus measures, and Nepal's Electronic Transactions Act 2063.
Worked example
Convert decimal 45 to binary, then to hexadecimal. Divide by 2 and record remainders: 45→1, 22→0, 11→1, 5→1, 2→0, 1→1. Reading bottom-up gives 101101. Check by weights: 32+8+4+1 = 45. Group the bits into nibbles from the right: 10 1101 → 0010 1101 → 2D in hexadecimal.
Traps that cost marks
Reading remainders top-down; calling a field a row; confusing SUB with FUNCTION; leaving HTML tags unclosed or placing title inside body; describing a query as a place to store data rather than to retrieve it.