For a first-year (10th-grade), high-school chemistry laboratory, pipettes and volumetric flasks are essential for the preparation of aqueous solutions of molecules, acids, bases, and transition-metal salts.
The Enrichment Chemistry Series™ laboratory is based upon the use of a Vernier spectrophotometer to measure the concentrations of color molecules and transition-metal salts. Starting with a stock solution that is created by adding a weighed transition-metal salt to a volumetric flask, a student can use pipettes to successively dilute the stock solution to produce a concentration that does not saturate the spectrophotometer. For strongly absorbing ions such as dichromate ion or permanganate ion, many dilutions are required.
Pipettes and volumetric flasks are my favorite labware. As a research chemical engineer, over a period of ten years I became skilled at the task of preparing solutions of known concentrations. Students should acquire and demonstrate mastery of this skill. Critical to the learning process is a pipette pump.
As a safety precaution, students should never pipette solutions by mouth. Many decades ago, when I was a stupid researcher, I did. At the time, I concluded that a mouthful of a strong base was much worse than a mouthful of a strong acid.