Arithmetic Grade Six

Lesson Twenty-eight: Number Chains


One rule that you should be aware of is that stuff inside of parenthesis must be computed before stuff without parenthesis. Let's take the following equation as an example.


      45 - 6 - ( 7 + 8 ) - 3 =

As your first step you ought to figure out that 7 + 8 = 15 and then transform the problem into:

      45 - 6 - 15 - 3 =

before proceeding. Obviously you could simplify the problem to 36 - ( 7 + 8 ) and then to 36 - 15, if you want, but the important thing to remember is that ( 7 + 8 ) must be solved before the minus sign which proceeds it is applied.

Here's another example:


      35 + ( 32 - 17 ) + 10 =

Here 32-17 must be solved before doing the rest of the problem. Here's the problem after this step:

      35 + 15 + 10 =

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