Fold
Noun and Suffix
ばい
ワニカニのレビューの数が四倍になってしまった。
WaniKani's review count has quadrupled.
クリスマスの日ぐらい、きゅうりょうを十倍にしてくれたっていいじゃないか！
Why not just pay me ten times more than usual on Christmas day at least?
回転寿司の普及に伴い、日本におけるサーモンの消費量は輸入開始から三倍となった。
Since the introduction and subsequent spread of conveyer belt sushi shops, salmon consumption in Japan has tripled.
Throw this onto a number and you have yourself the number of times something has increased. For example, ３倍 means something increased "three fold."
The reading is the same as the one you learned with the kanji. Omit the 〜 when writing out the answer, though. That just represents that there should be something before the kanji in this word when being used.