Divisibility Rules & Unit Digits
A high-yield practice drill on standard Divisibility Rules and Unit Digit calculation for Kerala PSC examinations (LDC, LGS, CPO, Fireman, Secretariat Assistant). Master shortcut divisibility tests ($$2, 3, 4, 5, 6, 8, 9, 10, 11$$), solving for missing digits to satisfy divisibility conditions, and unit digits in products and powers. Study Scope Divisibility Tests: Sum of digits ($$3$$ and $$9$$), last two digits ($$4$$), last three digits ($$8$$), alternating sum difference ($$11$$) Co-prime Composite Divisibility: Testing for $$6$$ ($$2 \times 3$$), $$12$$ ($$3 \times 4$$), $$15$$ ($$3 \times 5$$) Missing Digit Puzzles: Finding the smallest digit to make numbers divisible by $$3, 9$$, or $$11$$ Unit Digit Operations: Unit digits of arithmetic sums and large products Power Cyclicity: Cyclicity of base unit digits ($$2, 5, 6, 7$$) in power calculations Tested Competencies Instantly determine whether a multi-digit number is divisible without long division Identify missing digits in algebraic arithmetic expressions Rapidly compute unit digits of large powers and products Cover: Soroban Abacus (Public domain). Source: Wikimedia Commons. Changes: Cropped to 16:9 aspect ratio and resized to 1200x675.
