Worked example
A pipette delivers 25.0 cm³. To use it in moles = concentration × volume, the volume must be in dm³. 1 dm³ = 1000 cm³, so divide by 1000: 25.0 cm³ = 0.0250 dm³.
Check by size: a dm³ is much bigger than a cm³, so the number of dm³ must be smaller.