Why is 測 written in hiragana sometimes?


The dialog in [this PDF
document](https://www.nhk.or.jp/lesson/update/pdf/le10_en_t.pdf) has the word
はかります but when I search the word in romaji, only 測ります ([and some other
variations](https://www.tanoshiijapanese.com/dictionary/entry_details.cfm?entry_id=57977&element_id=76625&conjugation_type_id=5)),
show up in the results. Why is it that the kanji word 測 is written like はか for
that particular example?




There is no requirement to write words in kanji. A sentence written entirely
in hiragana would still be valid (if somewhat hideous to read).

Your PDF is clearly beginner level learning material. I would guess that the
writers of the material decided that the kanji for 測る was too advanced to
learn at that level. According to [this site](https://kanjicards.org/kanji-
list-by-grade.html) this kanji isn't learnt by school children until grade 5.

