## How good are you at calculating in your head? Are you calculator-dependent?

Improving mental arithmetic (calculating in your head) has been a long-term quest for me. My 3 daughters were subjected to numerical puzzle questions whenever we were on long journeys, and now none of them routinely use calculators, unless absolutely necessary.

I used to develop JavaScript-based apps for the webOS platforms in Palm and HP devices, and created a number of mental arithmetic apps. I’ve recently found the time to re-engineer some of them to work on Android devices, and the following apps can now be found on Google Play and Amazon Appstore:

• Arithmetic Brain – 8 different levels of 10 randomly generated questions about addition, subtraction and multiplication. Here are the links to Google Play and Amazon Appstore.

• Multiply Brain – 19 different levels of 10 randomly generated questions on multiplication from x2 to x20. Here are the links to Google Play and Amazon Appstore.

• Decimal Brain – 8 different levels of 10 randomly generated questions about decimal addition, subtraction and multiplication. Here are the links to Google Play and Amazon Appstore.

• Fraction Brain – 4 different levels of 10 randomly generated questions about fraction addition, subtraction, multiplication and division. Here are the links to Google Play and Amazon Appstore.

Full details about what is included in each Android app can be found on each app page.

Android 8.0 is coming very soon, so I have started preparing my apps for this new platform, while still maintaining the same functionality for Android versions back to 2.3.3 (Gingerbread). However, I will not be further updating my Chrome apps, as the Chrome Web Store has stopped accepting new apps, and is likely to stop hosting existing apps soon too.

The first paid-for app to be updated for Android 8.0, including 6 more questions, is:

and the 2 free apps, including samples from the other apps:

Update to more of my Android apps will follow shortly.

This is quick reminder that I still have the following apps available in Google Play:

• Data Steps: Do This in SAS?
• SQL: Do This in SAS?
• Graphs: Do This in SAS?
• Platforms: Do This in SAS?
• EG: Do This in SAS?
• Macros: Do This in SAS?
• Efficiency: Do This in SAS?
• Studio: Do This in SAS?

These apps are also available for Android users in the Amazon Appstore:

• Data Steps: How Do You Do This in SAS?
• SQL: How Do You Do This in SAS?
• Graphs: How Do You Do This in SAS?
• Platforms: How Do You Do This in SAS?
• EG: How Do You Do This in SAS?
• Macros: How Do You Do This in SAS?
• Efficiency: How Do You Do This in SAS?
• Studio: How Do You Do This in SAS?

There are also free apps, which you can find by searching in each app store:

• How Do You Do This in SAS? (Google Play and Amazon Appstore)
• Consulting: Do This in SAS? (Google Play)
• Consulting: How Do You Do This in SAS? (Amazon Appstore)

All these apps are updated frequently, and the paid-for apps are priced at less than US\$3 based on the number of questions that are answered, and within the apps you can ask new questions that can be added in future updates. It doesn’t matter which platform you use, as the same content is present in the corresponding Google Play and Amazon Appstore apps.