Assume 1 small bub side = 2cm
area = 2 × 2
= 4 cm²
total area of small bub
4 × 4 = 16cm²
area of big bub = total area of small bub
= 16cm²
one side of big bub
16 ÷ 4 = 4
1 small bub side : 1 big bub side
2 : 4
1 : 2
the side length of the large square is 2 times bigger than the side length of one small square.