# Type the missing number for 879x equals 8.79?

As 8.79 is a hundredth of 879 the missing number must be 0.01 so the sum should read 879 x 0.01 = 8.79

### How do you complete level 15 on 100 Floors?

The logic behind this level is that the part of the figure that is missing is where the number is on the keypad, so for the first figure over the door, the upper left corner is missing, where the number 1 is on the keypad. For the second figure, the right middle is missing, which is where the 6 is, etc. Type in the pass code 1643 to open the door.

### What is used to indicate the number of each type of atom in the naming of a covalent molecule?

One of the following prefixes: "mono" equals one; "di" equals two; "tri" equals three; "tetra" equals four; "penta" equals five; "hexa" equals six; "septa" equals seven "octa" equals eight; "nono" equals nine; "deca" equals ten; "undeca" equals eleven; and "dodeca" equals twelve. If the name of the element begins with a vowel, and the last letter of the preix as shown above is "a", the "a" is dropped from the prefix. Example: "pentoxide" instead of…

### Why you start a formula with an equal sign?

Without it, Excel will treat what you type in as a number, date or text. What you type will then literally appear in the cell. All functions start with letters. If the first thing you type is a letter, then it would be treated as text. The equals sign tells Excel to do the calculation that follows it. If you try typing any formula or function without an equals sign it will just appear in…