# Category: Formulas

## Apps - Migrating OnStart formula to use App.StartScreen/ Fixing existing apps that implement deep linking

A recent update to Power Apps now prohibits the use of Navigate in App.OnStart. Existing apps that call Navigate in App.OnStart will show the error 'Navigate is not permitted in OnStart. Use the StartScreen property instead.' How do we fix this problem? The post describes some of the possible solutions.

## Calculations - What mistakes can happen when we fail to use round brackets correctly in calculations?

What can go wrong when we fail to use brackets correctly in mathematical calculations? This post provides an example.

## Walkthrough - Solving maths puzzles with Power Apps

For learning purposes, it can be useful to see a practical example of how to carry out mathematical tasks with Power Apps. This post walks through a demonstration of how to answer a quiz question using Power FX functions that include ForAll, Sequence, and Mod.

## Formulas - Review of how to write formulas using natural language

During the Build conference in May 2021, Microsoft announced an innovative new feature - the ability to write formula using natural English words and sentences. This feature is now in preview, and this post takes an initial look at how this works.

## Formula - converting centimeters/meters to feet and inches, and vice versa

When building apps, particularly for audiences that include US and European users, there is often the requirement to convert measurements from centimeters/meters to feet and inches. This post covers the basic formula to carry out this task.

## Dates - 4 tips to make sure that dates display correctly in UK "dd mm yyyy" format

A common requirement for UK app builders is to configure canvas apps to aways accept and display dates in "dd/mm/yyyy" format.This post describes 4 tips to help ensure that date picker and label controls display dates as expected.

## Formulas - How to calculate the distance between 2 points

We can calculate the distance between two longitude and latitude co-ordinates using a trigonometric calculation. It's a complex formula so in this post, we'll find out how exactly this works, including a verification of the result. We'll see how to perform this distance calculation in both kilometers and miles.

## SharePoint - How to Patch the 6 most complex data types

With SharePoint, the syntax to patch certain data types can look very complicated. In this post, we'll summarise the syntax to patch lookup, single choice, multi-choice, yes/no, single person/group, and multi person/group columns.

## Formulas - Generating Row Numbers - Part 2

Here's a technique to display row numbers against a sorted set of data in a gallery control.

## Data - How to access nested collections/tables

If you're struggling to access records in nested collections/tables, here's some example syntax.

## Formulas - Show Running Totals

Find out how to show running totals within a gallery.

## Formulas - Generating Row Numbers

Find out how to display row numbers against records.