To drag the measurement to the equal length:
[tex]\begin{gathered} 1000mg\longrightarrow1g \\ 1000g\longrightarrow1\operatorname{kg} \end{gathered}[/tex][tex]\begin{gathered} 8000mg\longrightarrow x \\ 1000mg\longrightarrow1g \\ 8000mg\longrightarrow8g-\longrightarrow0.008\operatorname{kg} \end{gathered}[/tex]
For the first one,(8000mg) you can drag and drop these 8g and 0.008kg
[tex]\begin{gathered} 1000mg\longrightarrow1g \\ x-\longrightarrow80g \\ \text{cross multiply} \\ x=80\times1000=80000mg \\ \text{also} \\ 1000g\longrightarrow1\operatorname{kg} \\ 80g\longrightarrow x \\ x=\frac{80}{1000}=0.08\operatorname{kg} \end{gathered}[/tex]
For the second one, (80g) you can drag and drop these 80,000mg and 0.08kg
[tex]\begin{gathered} 1000g\longrightarrow1\operatorname{kg} \\ x-\longrightarrow0.8\operatorname{kg} \\ x=0.8\times1000=800g \end{gathered}[/tex]
For the third one, (0.8kg) you can drag and drop these 800g
