Round of the measurement to 3 significant figures,. 1764.9 ml. and . 0.007 498 3 times 10 to the 4th power

You can think of 1764.9 mL to 3 significant figures as "3 digits" so, you will first simplify to

1.7649x10^3 ml then, since they want 3 digits,

1.76×10^3

0.0074983=7.4983×10−3

3 significant figures as "3 digits",

7.50×10−3
Hope this helps