Things and the gaps between them, step by step

A log sawn into five pieces takes four cuts.

The question

How many cuts does that take?

The things, or the gaps between them

pieces:15

●—●—●—●

Here is what the question hands over, before any counting.
The numbers give you one count straight away: 15 pieces. That is almost always what a child writes down.
Before answering, look at a small row — four dots and the gaps between them. The question asks for something one step away from that count, and which way depends on where the ends are.
Cuts sit BETWEEN the pieces, not at the ends: 15 pieces have 15 − 1 = 14 cuts. Break a stick in two and you cut once.

How it works.

01
Here is what the question hands over, before any counting.
02
The numbers give you one count straight away: 15 pieces. That is almost always what a child writes down.
03
Before answering, look at a small row — four dots and the gaps between them. The question asks for something one step away from that count, and which way depends on where the ends are.
04
Cuts sit BETWEEN the pieces, not at the ends: 15 pieces have 15 − 1 = 14 cuts. Break a stick in two and you cut once.