Simplifying · Just Numbers · A6

Going negative.

When you subtract more than you have, the result is negative. Negatives behave like a number line: moving left past zero. This sets up negative coefficients later.

01 / THE IDEA

See it simplify.

One step at a time

Do the strongest operation first.

0 / 2
3 - 7 + 2
— / WHY IT WORKS

The idea underneath.

Below zero

On a number line, subtracting moves left. 3 − 7 = −4. Adding a positive moves right again: −4 + 6 = 2.

Why it works

Temperature: 3 degrees, drop 7, you are at −4.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

6 - 7 + 4

1

Step

6 - 7 = -1

2

Step

-1 + 4 = 3

EX 2medium

6 - 10

1

Step

6 - 10 = -4

EX 3hard

11 - 18

1

Step

11 - 18 = -7

04 / COMMON TRAPS

Where students slip.

Trap

3 − 7 = 4 (ignoring the sign).

Fix

It is −4 — you crossed below zero.

Trap

Two minuses confusion.

Fix

Take it one step at a time on the number line.

05 / QUIZ

Test yourself.

The Test

12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.

0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).
Core

Core (4)

C1

6 - 7 + 4

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
C2

5 - 7 + 6

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
C3

4 - 5 + 5

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
C4

6 - 9

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
Apply

Apply (4)

A1

6 - 10

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
A2

4 - 9 + 4

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
A3

5 - 8 + 3

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
A4

8 - 17

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
Extension

Extension (4)

E1

11 - 18

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
E2

8 - 9 + 8

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
E3

11 - 15 + 6

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.
E4

12 - 19

Need a hint?
  • Picture a number line; subtract moves left.
  • If you pass zero, the result is negative.