What significant technologies would be lost in a world without "Advanced" Mathematics? Specifically, what technologies required to get to the next level of scientific progress in an area would be lost. Your largest constraint is algebra. The humans on this world can count to small numbers, they can perform addition, subtraction, comparison, and other mathematics operations below the level of multiplication and addition on whole integers, you may consider variables as part of our working algebra set and zero may or may not exist.
I realize some basic Chemistry might be possible and that tinkering with ratios might lead to division since a ratio can be expressed that way, yet it may also be ignored like the number zero in our own history. So unless something explicitly requires more advanced math it is not removed as a possibility. Modern Chemistry, however, would definitely be removed as we play with algebra too much.
Geometry and Logic as areas of Mathematics have special consideration. Logic can be formulated without advanced algebra, although its level of utility and formalization may depend on it. Geometry is constrained to matching shapes and lengths as well as other things that are capable of being eyeballed. Anything beyond that should be kept to a minimum.
As a good test to constrain your technologies, ask if processes can be done via a "match" unit versus a unit requiring conversion. If you can directly perform comparisons it can be done with minimal math. Conversion of units however requires multiplication or division and is not allowed.