7IF we MULTIPLY by 7 in 28, then28 × 7 = 196196 = 2 × 2 × 7 × 7√196 = √(2 × 2 × 7 × 7) = 14Now, we can say 196 is PERFECT square.∴ The LEAST number is 7 which, when MULTIPLIED by 28, forms a perfect square.