1．1.09m等于（ 1090 ）mm
2．∵已知需求出1.09m等于多少mm
1米(m) = 1 × 1000 = 1000毫米(mm)
∴1.09m = 1.09 × 1000
= 1090mm
3．答：1.09m等于1090mm
