Zero Kelvin is the same as absolute zero. Temperature is a property of matter that can be measured using a thermometer. Kilo- means 1000. The arrow heads shown are about 3 centimeters. The factor must be 1 or greater but less than 10.
Estimation saves time and is a valuable skill.
Any value can be a standard as long as it is agreed upon. For example, if your teacher gives you a piece of string as a standard, you can measure objects in the classroom. For 0.0063, get the number 6.3. First, 6.3 divided by 10 yields 0.63. For 6300, get the number 6.3.