It mayu help is you look at these examples before you start. Using an Accumulator

## Using an accumulator to add.

The variable `list` is an array, it holds several integers. For example it might be the list {1,2,3,4}.

You can iterate over a list, every time you visit an element of the list you do something to the accumulator `acc`

In this example, for every member `v` of the list you add that member to the accumulator using the code

```acc = acc + v;
```

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## Using an accumulator to count.

Use the accumulator to count the number of items in the list:

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## Using an accumulator to multiply.

Use the accumulator to find the product of items in the list:

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## Using an accumulator to max.

Use the accumulator to find the largest item in the list:

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## Count Twos.

Use the accumulator to find the number of twos in the list: Count on a condition

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## Count Non-Twos.

Use the accumulator to find number other than 2:

```f({1,1,1,1})             -> 4
f({2,2,2})               -> 0
f({1,1,1,1,1})           -> 5
f({4,2,6,0,0})           -> 4
```

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## Count the big numbers

Use the accumulator to count all numbers larger than 1:

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