First Law of Indices

- If there is no visible sign before a number, the invisible sign is PLUS e.g. 8 means +8
- If two numbers have the same signs in front of them, the answer has that sign and you ADD the two numbers e.g. -1-2=-3 and 4+3=7
- If two numbers have opposite signs in front of them, the answer has the sign of the larger number and you SUBTRACT the smaller number from the larger number e.g. 4-7=-3 and 8-7= 1
- If the two numbers are equal in value but have different signs in front of them, then the result is zero e.g. -9+9= 0 and 15-15=0

Related to Sample Lesson

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First Law of Indices

VACANT

VACANT

VACANT

209

920

VACANT

VACANT

18 parts of 21 can be represented as

18−21

21÷18

18+21

21×18

18÷21

74 parts of 89 can be represented as

74+89

89÷74

74÷89

89×74

74−89

21 parts of 72 can be represented as

VACANT

VACANT

VACANT

5 parts of 12 can be represented as

12÷5

5×12

12+5

5÷12

5−12

VACANT

VACANT

VACANT

136

613

VACANT

VACANt