Obviously all conversions need multiplication, here's their answers: a. [tex] dm\times \frac{1m}{10dm} = m[/tex] b. [tex]m \times \frac{1km}{1000m} = km[/tex] c. [tex]km \times \frac{1m}{0.001km} = m[/tex] d. [tex]mm \times \frac{1cm}{10mm} = cm[/tex]
