# What is 8 8 4 12

### Adding and subtracting a positive Number:

\$\$( +5 ) + ( + 9 )\$\$ \$\$ =5 + 9 = 14\$\$
↙     ↘
instead of \$\$ (+ 5) \$\$ instead of \$\$ (+ 9) \$\$
\$\$5\$\$           \$\$9\$\$

\$\$( +12 ) - ( + 23 )\$\$ \$\$ =12 -23 = -11\$\$
↙     ↘
instead of \$\$ (+ 12) \$\$ instead of \$\$ (+ 23) \$\$
\$\$12\$\$           \$\$23\$\$

### Adding and subtracting a negative Number:

\$\$( - 8 ) - ( - 14 ) \$\$ \$\$=( - 8 ) + ( + 14 )\$\$ ↘
Subtracting \$\$ (- 14) \$\$
\$\$ =- 8 + 14 = 6\$\$
↙
instead of \$\$ (- 8) \$\$
\$\$-8\$\$

\$\$(- 13 ) - ( + 16 ) = - 13 + ( -16 )\$\$ ↘
Adding \$\$ (- 16) \$\$ means
subtract from \$\$ (+16) \$\$
\$\$=- 13\$\$ \$\$ – 16 = - 29\$\$
↙
instead of \$\$ (- 13) \$\$
\$\$-13\$\$

Subtracting a number is the same as adding the opposite number

### Bracket rules for addition and subtraction

##### 1st example: sign of the bracket "\$\$ + \$\$"

Step 1: Release the clamp

\$\$12 + ( 8\$\$ \$\$– 4 ) = 12 + 8\$\$ \$\$– 4 \$\$

2nd step: Combine numbers with the same sign

\$\$12 + 8\$\$ \$\$– 4 = 20\$\$ \$\$– 4 \$\$

3rd step: Group numbers according to the sign rules

\$\$20\$\$ \$\$– 4 = 16\$\$

A “\$\$ + \$\$” in front of the brackets means that the signs do not change when the brackets are broken!

##### 2nd example: sign of the bracket "\$\$ - \$\$"

Step 1: Release the clamp

\$\$28 - ( 6 + 4 ) = 28\$\$ \$\$– 6 - 4 \$\$

2nd step: Combine numbers with the same sign

\$\$28\$\$ \$\$– 6\$\$ \$\$– 4 = 28 - 10\$\$

3rd step: Group numbers according to the sign rules

\$\$28\$\$ \$\$– 10 = 18\$\$

A “\$\$ - \$\$” in front of the brackets means that the signs change when the brackets are broken!

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