Word Hike One of Aryabhata's most important contributions is his approximation of "pi", he also gave the world the number ____ answer

Below you will find the Word Hike "One of Aryabhata's most important contributions is his approximation of "pi", he also gave the world the number ____" answers. This is a brand new word game developed by Joy Vendor. Word Hike is a themed puzzle games. You will be given a puzzle covering a specific theme and you must fill the puzzle’s rows with answers. To unlock the word of every row, you must solve a clue provided by the game. In other words, you must figure out the clues twists to arrange the crossword-like puzzle in all Word Hike levels. More variety of challenging levels, find answers by looking at pictures, challenge your mind in a whole new way. Travel around the world, every level is a new destination! It will challenge your knowledge and skills in solving crossword puzzles in a new way. As you find new word the letters will start popping up to help you find the the rest of the words.
If you still can’t figure it out please comment below and will try to help you out.