What about −(−6) ? What quantity is in the box?

What quantity is now in the box? + 6 What quantity is now in the box?

What quantity is now in the box? − 6 What quantity is now in the box?

What quantity is now in the box? + 6 − 6 What quantity is now in the box?

What quantity is now in the box? −(−6) means remove −6 + 6 − 6 What quantity is now in the box? Therefore −(−6) means remove −6 this gives a + 6 Therefore −(−6) = + 6

What about +(− 6) ? What quantity is in the box?

What quantity is now in the box? + 6 What quantity is now in the box?

What quantity is now in the box? − 6 What quantity is now in the box?

What quantity is now in the box? + 6 − 6 What quantity is now in the box?

What quantity is now in the box? +(−6) means add −6 + 6 − 6 − 6 What quantity is now in the box? Therefore +(−6) means add −6 this gives a −6 Therefore +(−6) = − 6

What about −(+ 6) ? What quantity is in the box?

What quantity is now in the box? + 6 What quantity is now in the box?

What quantity is now in the box? − 6 What quantity is now in the box?

What quantity is now in the box? + 6 − 6 What quantity is now in the box?

What quantity is now in the box? −(+6) means remove +6 + 6 − 6 What quantity is now in the box? Therefore −(+6) means remove +6 this gives a −6 Therefore −(+6) = − 6