Chapter 10: The Other Side of Zero
What is below the ground floor, colder than freezing, or less than nothing in your bank account? Negative numbers! In this chapter we ride a lift through floors below zero, add and subtract with tokens, meet integers in money, temperature and heights, and solve integer puzzles.
In this chapter you will
- use positive and negative numbers for floors, money, temperature and heights
- compare and order integers on a number line
- add and subtract integers using tokens and the number line
- solve puzzles and spot patterns with integers
Topics
- A Building of Fun NCERT 10.1
Integers: …, −3, −2, −1, 0, +1, +2, +3, … Negative numbers are below (or left of) zero.
- The Token Model NCERT 10.2
Green = +1, coral = −1; a green and a coral make a zero pair (0).
- Integers in Other Places NCERT 10.3
Integers describe money in and out, temperatures below zero, heights below sea level, and scores.
- Explorations with Integers NCERT 10.4, 10.5
A missing number = the total − the numbers you know.
Key words
- Integer
- a whole number, zero, or the negative of a whole number: …, −2, −1, 0, 1, 2, …
- Positive number
- a number greater than zero
- Negative number
- a number less than zero, like −3
- Zero pair
- a +1 and a −1 together, worth 0
- Opposite
- the number the same distance from zero on the other side (3 and −3)
Summary
- Integers are …, −3, −2, −1, 0, 1, 2, 3, … Negative numbers are less than zero.
- On a number line, numbers increase to the right; −1 is greater than −5.
- A positive and a negative token make a zero pair; zero pairs do not change the value.
- Subtracting a number is the same as adding its opposite.
- Integers describe floors below ground, debts, temperatures below 0 °C and depths below sea level.