Integers · Add integers · 4.5

Add three or more.

To add a chain of integers, work left to right — or group the positives and the negatives, total each, then combine the two.

01 / THE IDEA

See it work.

Watch the method

Add three or more

−3 + 5 + (−4): running total −3, then 2, then −2.

1 / 2
−3+5+−4-3 + 5 + -4
1

Add

-3 + 5 = 2

2+−42 + -4
2

Add

2 + (-4) = -2

−2-2
02 / YOUR TURN

Practice until it feels automatic.

Your turn

Work it out.

Type a whole number — negatives allowed, e.g. -7.

streak 0
best 0
… =
— / WHY IT WORKS

The idea underneath.

One step at a time

Addition is associative: keep a running total, applying each number in turn.

Why it works

Tally gains and losses as you go.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

Add 8 + 7 + 9

1

Add

8 + 7 = 15 15 + 9

2

Add

15 + 9 = 24 24

EX 2medium

Add -4 + -7 + -5

1

Add

-4 + (-7) = -11 -11 + -5

2

Add

-11 + (-5) = -16 -16

EX 3hard

Add 9 + -6 + -9

1

Add

9 + (-6) = 3 3 + -9

2

Add

3 + (-9) = -6 -6

04 / COMMON TRAPS

Where students slip.

Trap

Losing track of the running sign.

Fix

Carry the running total carefully.

Trap

Adding sizes and guessing the sign.

Fix

Apply each number with its sign.

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

Add 8 + 7 + 9

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
C2

Add -3 + -2 + -1

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
C3

Add -9 + -8 + 4

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
C4

Add -6 + -5 + 5

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
Apply

Apply (4)

A1

Add -4 + -7 + -5

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
A2

Add -6 + -8 + 5

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
A3

Add 1 + -6 + 1

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
A4

Add 3 + -1 + 8

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
Extension

Extension (4)

E1

Add 9 + -6 + -9

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
E2

Add 5 + 8 + -5

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
E3

Add -8 + 7 + -3

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.
E4

Add 9 + 6 + -8

Need a hint?
  • Keep a running total.
  • Or total the + and − groups, then combine.