hosuukei no hosuu wo kirokuhyou ni kaku.

It is read:

ほすうけい の ほすう を きろくひょう に かく。

Word by word:

• 歩数計（ほすうけい） = pedometer / step counter
• の = links nouns, often like of
• 歩数（ほすう） = number of steps, step count
• を = marks the direct object
• 記録表（きろくひょう） = record sheet / chart / log
• に = indicates the place or target of writing
• 書く（かく） = to write

So the structure is basically: write the pedometer’s step count on the record sheet.

They are related, but they mean different things:

• 歩数計 = step-count device
  
  • 歩数 = number of steps
  • 計 = meter / counter / measuring device

So 歩数計 literally means something like step-count meter.

• 歩数 by itself means the number of steps.

In this sentence:

• 歩数計 = the device
• 歩数 = the data shown by that device

So 歩数計の歩数 means the pedometer’s step count or the number of steps on the pedometer.

Here, の connects two nouns. A very natural translation is of or ’s.

So:

• 歩数計の歩数 = the step count of the pedometer = the pedometer’s step count

This use of の is extremely common in Japanese. It often shows possession, relationship, category, or specification.

A few similar examples:

• 先生の本 = the teacher’s book
• 日本の車 = a Japanese car / a car from Japan
• 学校の名前 = the school’s name

In your sentence, の shows that the 歩数 belongs to or comes from the 歩数計.

を marks the direct object of the verb.

The verb here is 書く = to write.

What are you writing?

• 歩数 = the step count

So:

• 歩数を書く = write the step count

That is why 歩数 takes を.

With 書く, に often marks the place or surface where something is written.

So:

• 記録表に書く = write it on the record sheet

This is similar to:

• 紙に書く = write on paper
• ノートに書く = write in a notebook
• 黒板に書く = write on the blackboard

So in this sentence:

• 歩数を = what you write
• 記録表に = where you write it

Usually, に is the natural choice here.

• 記録表に書く = write on/in the record sheet

If you use を with 書く, it normally marks the thing being written, not the place where you write it.

For example:

• 名前を書く = write your name
• 数字を書く = write numbers

So in your sentence:

• 歩数を is already the thing being written
• 記録表に is the place it gets written

That combination is standard and natural.

Because Japanese normally places the verb at the end of the sentence.

So the pattern is often:

[topic/subject] [object] [place] [verb]

Here:

• 歩数計の歩数を = the pedometer’s step count
• 記録表に = on the record sheet
• 書く = write

This word order is very normal in Japanese.

The subject is omitted, which is very common in Japanese.

Japanese often leaves out information that is obvious from context. So this sentence does not explicitly say:

• I write
• you write
• please write
• one writes

Depending on context, it could mean things like:

• Write the pedometer’s step count on the record sheet.
• I write the pedometer’s step count on the record sheet.
• We write the pedometer’s step count on the record sheet.

In isolation, it often feels like an instruction, a label, or a simple statement in plain form.

書く is the plain/dictionary form of the verb.

Japanese uses the plain form in many situations, such as:

• casual statements
• instructions in manuals or worksheets
• captions or labels
• dictionary-style expressions
• notes describing actions

書きます is the polite form.

So:

• 書く = plain
• 書きます = polite

In something like a workbook, health log, or instructions, 書く is very natural.

It can, depending on context, but not as strongly as an explicit command.

By itself, 書く in plain form can sound like:

• a simple action description
• a step in a procedure
• an instruction in a manual
• a heading or label

If you wanted a clearer direct command, you might see:

• 書いてください = please write
• 書きなさい = write! (more forceful, often used by teachers/parents)

So 歩数計の歩数を記録表に書く。 often feels like Write the pedometer’s step count on the record sheet in the style of a brief instruction.

Yes, Japanese word order is somewhat flexible, as long as the particles stay correct.

For example, these are possible:

• 歩数計の歩数を記録表に書く。
• 記録表に歩数計の歩数を書く。

Both are understandable and natural.

The particles tell you the role of each part:

• を = object
• に = place/target

So the meaning stays clear even if the order changes somewhat.

That said, the original order is very straightforward and natural.

It is natural, but not the only possible wording.

Depending on context, Japanese might also use shorter expressions if the meaning is already clear, such as:

• 歩数を記録表に書く。
  = Write the step count on the record sheet.

If everyone already knows the steps come from the pedometer, 歩数計の may be unnecessary.

But 歩数計の歩数 is useful when you want to be precise: it clearly says that the number being written is the one shown by the pedometer.

記録表 means a record sheet, log sheet, chart, or table used for recording information.

It is made from:

• 記録（きろく） = record, recording
• 表（ひょう） = chart, table, form

So it suggests some kind of organized place where information is entered, rather than just any piece of paper.

That fits well with a sentence about writing down step counts regularly.