You know that 10mm are equal to 1cm
Then you can find the value in cm of the given mm using a rule of three:
You get then the formula:
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Then you use that formula and get:
1mm: 1/10cm
5mm: 5/10cm=1/2cm
15mm: 15/10cm=3/2cm
30mm: 30/10cm=3cm
60mm: 60/10cm=6cm
100mm: 100/10cm=10cm
To find the value in mm of the given cm you use again a rule of three:
You get the general formula:
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Then you use that formula and get:
8cm: (8cm*10)mm=80mm
The proportional relationship 1/10 represents that for every mm there are 1/10cm
The constant of proportionality is the value you multiply to know the change in the number of cm when the mm change in this case 1/10.
The value that belongs to the 1mm in the table is 1/10 it means that 1mm is equal to 1/10cm