Hey there :)
Without using a calculator it is not hard to identify where it lies.
√88
Which are the perfect squares before and after √88 ?
√81 which is 9 and √100 which is 10
Therefore, √88 is between 9 and 10
In case you use a calculator, we can see that:
√88 = 9.38
9 < 9.38 < 10
[tex]\boxed {Your \ answer \ will \ be \ 9 \ and \ 10} [/tex]