Add three or more integers
key notes :
An integer is a number without a fractional part. Integers can be positive, negative, or zero.
You can add and subtract integers. Read on to learn how!
Adding integers on a number line
You can use a number line to add integers. Follow these steps:
- Find the first addend on the number line.
- Add the second addend. To add a positive number, move to the right. To add a negative number, move to the left. The sum is where you land.
Adding a positive integer
Let’s try it. Add –3+5.
Find –3 on the number line. Since 5 is positive, move 5 units to the right.
Since you land on 2, the sum is 2.
So, –3+5=2.
Adding a negative integer
Let’s try another one. Add 4+(–7).
Find 4 on the number line. Since –7 is negative, move 7 units to the left.
Since you land on –3, the sum is –3.
So, 4+(–7)=–3.
Rules for adding integers
You can add integers without number lines. Use the signs of the addends to help you solve!
- If the addends have the same sign, add the absolute values of the addends, and give the sum that sign.
- If the addends have different signs, subtract the lesser absolute value from the greater absolute value, and give the sum the sign of the addend with the greater absolute value.
Adding integers with the same sign
Let’s try it. Add –4+(–6).
The signs of the addends are the same, so add their absolute values.
|–4|+|–6|=4+6=10
Since both addends are negative, the sum is also negative.
So, –4+(–6)=–10.
Adding integers with different signs
Let’s try another one. Add –4+6.
The signs of the addends are different, so subtract the lesser absolute value from the greater absolute value.
|6|–|–4|=6–4=2
Since the positive addend, 6, has a greater absolute value, the sum is positive.
So, –4+6=2.
Learn with an example
Add 16 + 6 + 14 + -10 =
First add 16 and 6:
16 + 6 + 14 + –10 = ?
22 + 14 + –10 = ?
Now add 22 and 14:
22 + 14 + –10 = ?
36 + –10 = ?
Now add 36 and –10:
36 + –10 = 26
The sum is 26.
Add -4 + 15 + 15 + 8 =
First add –4 and 15:
–4 + 15 + 15 + 8 = ?
11 + 15 + 8 = ?
Now add 11 and 15:
11 + 15 + 8 = ?
26 + 8 = ?
Now add 26 and 8:
26 + 8 = 34
The sum is 34.
Add 9 + 17 + -2 =
First add 9 and 17:
9 + 17 + –2 = ?
26 + –2 = ?
Now add 26 and –2:
26 + –2 = 24
The sum is 24.
let’s practice !