Description: 👉 Learn how to find the partial sum of an arithmetic series. A series is the sum of the terms of a sequence. An ...

👉 Learn how to find the partial sum of an arithmetic series. A series is the sum of the terms of a sequence. An arithmetic ...

These little geniuses can crack complex three digit arithmetic sums in seconds. In fact, they can even attempt as many as 70 arithmetic sums in just 5 minutes. Their trick is mental maths with the ...