The students in math class use square tiles to make arrays. If they
- use 8 (8=1·2·2·2) tiles, then they can form arrays of the length in 1 tile, 2 tiles, 4 tiles and 8 tiles;
- use 9 (9=1·3·3) tiles, they can form arrays of the length in 1 tile, 3 tiles and 9 tiles (one array less).
So, you can conclude that Celia is correct.
2/10 in simplest form is 0.2
