Question

How many millimeters are in 3 km?

Answer 1

`3Km= 3,000,000 mm`

Explanation:

The units from Biggest on the left to smallest on the right are:

`color(red)(Km)color(white)(xxx) Hmcolor(white)(xxx) Dmcolor(white)(xxx) color(red)(m) color(white)(xxx)dmcolor(white)(xxx) cmcolor(white)(xxx) color(red)(mm)`

The conversion factor between any of the adjacent units is 10.

`larr xx 10 and rarr div 10`

`Km xx1000rarr m xx 1000rarr mm` To convert big to small.

`Km larr 1000 div m larr 1000 div mm`To convert small to big.

When you convert a value to a bigger unit, the number gets smaller. (There are fewer of them.) This is done by dividing

When you convert a value to a smaller unit, the number gets bigger.(There are more of them.) This is done by multiplying.

Km is the biggest distance of the metric system. (Just more than half a mile.)

mm the smallest of the usual lengths in the metric system.
(About 25 mm makes 1 inch)

To convert 3 Km to mm, write 3 under Km and fill in a 0 under each of the other units

`color(red)(Km)color(white)(xxx) Hmcolor(white)(xxx) Dmcolor(white)(xxx) color(red)(m) color(white)(xxx)dmcolor(white)(xxx) cmcolor(white)(xxx) color(red)(mm)`

`color(red)(3)color(white)(xxxxxx) 0color(white)(xxxxx) 0color(white)(xxxx) color(red)(0) color(white)(xxxx)0color(white)(xxxx) 0color(white)(xxxx) color(red)(0.)`

The decimal point shows what the unit is.

`3Km= 3,000,000 mm`

`3Km xx 1000 rarr 3000m " then " xx1000 rarr 3,000,000mm`