In meter, centimeter and millimeter largest unit is meter, then centimeter and then milimeter. For conversion 1 m=100 cm, 1 m=1000 cm.
Convert all the number to same unit for compare with each other.
First option is 7560 m.
Second option is,
[tex]7.56\times10\text{ cm}\times\frac{1\text{ m}}{100\text{ cm}}=0.756\text{ m}[/tex]
Third option 7.56 m is already in meter.
Consider the fourth option,
[tex]7.56\times10^4\text{ m=75600 m}[/tex]
Consider option fifth,
[tex]7.56\times10^4\text{ cm}\times\frac{1\text{ m}}{100\text{ cm}}=756\text{ m}[/tex]
Now check which digit is largest.
Largest is 75600 so first blank digit is ,
[tex]7.56\times10^4\text{ m}[/tex]
Second larget is 7560. So second blank digit is 7560 m.
Third largest is 756 m, So third blank digit is,
[tex]7.56\times10^4\text{ cm}[/tex]
Fourth largest is 7.56 m so in fourth blank digit is,
7.56 m
Fifth largest or smallest digit is 0.756 m. So in last blank digit is,
[tex]7.56\times10\text{ cm}[/tex]
