# Item Groups. Improving the efficiency of calculations

Hello everyone!

For those who appreciate the effectiveness of calculations in QM, I will show here how to select information from grouped items of categories. **Purpose**: to demonstrate the benefits and capabilities of QM. The result of the demonstration will be to reduce the number of formulas to a single one. A small number of formulas to achieve the result is one of the significant advantages of QM. How to achieve this advantage, I will show below on two cases known to experienced QM users. Sampling from item groups and recursion by item groups are not always obvious and easy to use. Therefore, it is on the item groups that I focus my attention. So let’s take a look.

**Case 1**. The “T**ime Demo. model**” model I saw in this post.

“A*uthor has taken the approach to put all time elements (months, quarters and year total) within a single time category. He then creates four formulas to obtain the quarterly values…*”

I reproduced part of this model and the author’s logic on dummy data in

**Variant 1**(Formulas 4 through 7).

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In

**Variant 2**, QM did the same calculations for quarterly values with just one formula (Formulas 8). Formulas 8 logic can also be implemented based on the

**SelectBetween**() function:

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