@dwrb42 question, in chapter 9 there are 730 slimes not 760. In the novel, 730 slimes split after cleaning 1st pit resulting in 1464 slimes. However, author writes there is only 1 slime that splits twice, so the math doesn't match up. The translators said there's no typo, so the author messed up. It should be 2 slimes.
@theldras question, your 1st guess is correct. They indeed split twice, but only a number of them not all. If my math correct, only 523 out of 1464 slimes split twice.