🤨 Why can my client add – but not subtract?


After an acquired brain injury, subtraction often breaks down before addition. Not because it’s “harder math," but because it tends to place greater demands on working memory and executive function (Dehaene et al., 2003).

Try this in your head:

Most people get this quickly. 5 tens plus 7 ones = 57.


Let's do another:

This time, you have to hold 40 in your mind, subtract 10, then subtract 7 - mentally tracking each step to get 23.

Same numbers. Different cognitive load.

That extra mental tracking helps explain why subtraction can be slower, more error-prone, or more fatiguing after brain injury – even when addition is relatively intact.

🚀A New Numbers Treatment – Mental Math: Subtraction

To make this easier for you to address and give your clients the intensity they need, we’ve added a new treatment to the Virtual Rehab CenterMental Math: Subtraction.

Clients subtract numbers in their head, with difficulty that automatically adjusts based on their performance. Optional supports, like written and spoken number words or visual hints, can be used as needed.

Accuracy and response times are tracked for you. 🙌

You bring the clinical expertise. The Virtual Rehab Center just makes it easierless prep time, built-in data, and ready-to-use treatments and homework.

Try it free for 21 days and see for yourself!

Subtraction may be about taking numbers away, but the work you do adds up to more independence each day. Thanks for the care you bring to every session. ✨

All the best,

-Megan

P.S. The Virtual Rehab Center has 50+ treatments, with new ones coming each month. Check out this growing list!

P.P.S. When mental math becomes easy, you can level up with Solving Time Problems and Solving Money Problems – language-rich, ADL-based challenges that increase cognitive-linguistic load with no extra prep! 🕺

Tactus Therapy

We're a speech therapy software company making evidence-based treatment for adults with stroke, brain injury, and other conditions more accessible.

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