In a phonetic language, each letter has one sound and each sound has one letter. Thus, if you know how to spell a word, you know how to pronounce it. If you know how to pronounce a word, you know how to spell it.
Russian is a highly phonetic language, very close to perfectly phonetic. As a result, you can read Russian words and know how they sound despite not recognizing them. Two weeks into my Russian studies, my partner and I began reading together. One would read a book aloud while the other followed along and corrected mispronunciations. We read as fast as we could, made frequent mistakes, and improved quickly. We did not understand anything that we read.
Once we became proficient in reading, which took a couple of weeks, we returned to vocabulary and grammar. We learned at an astonishingly faster pace than we did before our reading practice, as all of our studies became more efficient. We no longer sounded out words and double checked that we did so correctly. We were more confident when working through grammar books and flashcards. When we learned words, we could read and recognize them on sight, comfortable with the letters which comprised them.
Since all Russian studies depend on its alphabet, understanding the letters makes everything else easier. Despite that, most only study the alphabet the minimal amount before moving on to other things. They indirectly practice the alphabet while studying vocab or grammar instead of directly practicing it. They master the letters in the end, but it takes much longer.
In mathematics, arithmetic is the fundamental skill. All mathematical problem solving is built upon a foundation of arithmetic. With a weak foundation, solving math problems is greatly slowed. Unlike the alphabet, many math students never gain a mastery of arithmetic, and it perpetually harms them.
When in class, teachers explain problems without giving time for processing the arithmetic, assuming mastery in their students, and the students become lost. When doing homework, logic is interrupted by slow arithmetic. It is hard to keep a train of thought when you have to stop and count on your fingers or use a calculator to avoid mistakes.
Many students resent math because their grades suffer from arithmetic errors, which they consider unrelated to what they are being tested on. Math is the subject of perfect solutions. If you cannot obtain the solutions, for any reason, then you do not merit the grade.
If you want to improve mathematical ability, before anything else, check arithmetic skills. A calculus student who is falling behind would be best served by practicing arithmetic, assuming they are not proficient in it. Once mastered, their calculus studies will vastly improve.
If you would like to check your arithmetic skills,
here is a simple option. If you can solve 40 problems in under 1 minute, you are proficient. It does not matter how many tries you take.