To form a cube from cuboids, we need to determine how many cuboids are required to make up the dimensions of the cube.

Let's break down the problem into smaller steps:

**Step 1: Determine the dimensions of the cube:**
The sides of the cuboid are given as 2cm, 1cm, and 1cm. To form a cube, all sides of the cube should be equal. Therefore, the dimension of the cube will be 2cm x 2cm x 2cm.

**Step 2: Calculate the volume of the cube:**
The volume of a cube is given by the formula V = s^3, where s is the length of any side of the cube. In this case, the volume of the cube will be V = 2cm x 2cm x 2cm = 8cm^3.

**Step 3: Calculate the volume of a single cuboid:**
The volume of a cuboid is given by the formula V = l x b x h, where l, b, and h are the length, breadth, and height of the cuboid, respectively. In this case, the volume of a single cuboid will be V = 2cm x 1cm x 1cm = 2cm^3.

**Step 4: Determine the number of cuboids required:**
To find the number of cuboids required to form a cube, we need to divide the volume of the cube by the volume of a single cuboid.

Number of cuboids required = Volume of the cube / Volume of a single cuboid
Number of cuboids required = 8cm^3 / 2cm^3
Number of cuboids required = 4

Therefore, Namita will need 4 such cuboids to form a cube.

In conclusion, Namita will need 4 cuboids of dimensions 2cm x 1cm x 1cm each to form a cube.