Veda Bites are swipeable micro-lessons — each one teaches exactly one
idea. Here's a taste from this kit; the app has the full deck.
💡 Key Idea
A press is a signed number
Two buttons, one number.
One press of plus lifts the car by a floor and one press of minus drops it by a floor. So +2 means two floors up and -3 means three floors down. The sign gives the direction and the digits give the distance.
💡 Key Idea
Why the entrance is Floor 0
Start from the entrance.
The entrance is where you walk in, so reaching it asks for no press at all. Give it the number 0. Every other floor is then named by the press that takes you there from the entrance.
💡 Key Idea
Positive above, negative below
Above and below get signs.
Floors above the entrance carry positive numbers such as +1 and +2. Floors below it carry negative numbers such as -1 and -2. One signed number is enough to name any floor in the tower.
💡 Key Idea
The higher floor is greater
Higher wins.
Read two floors as places in the shaft. Whichever one sits higher is the greater number. Floor -2 is two floors under the entrance and Floor -5 is five under it, so -2 > -5.
💡 Tip
The bigger digit trap
Do not trust the digits.
After a minus sign, bigger digits mean a lower floor. A lower floor is a smaller number. So -9 is smaller than -3, even though 9 is bigger than 3. Read the place, not the digit.
💡 Key Idea
Below zero and above zero
Zero is the divider.
Every negative number is less than 0 because it names a floor under the entrance. Every positive number is greater than 0. A positive number therefore beats any negative one, whatever its digits.