Dyscalculia is a neurodiverse learning difficulty that affects a
person's ability to understand, remember, and manipulate numbers
and mathematical concepts. It is often referred to as "maths
dyslexia" and can manifest as difficulties with basic arithmetic,
understanding time, using money, and comprehending mathematical
concepts and formulas. This condition varies in severity and often
requires tailored educational strategies and interventions to help
individuals manage and overcome their challenges.

#### Getting started

Use the keyboard to enter the formula to be calculated. The answer
will be displayed immediately. For example:

1 +
2 = 3

- Press the ▲ Shift key to access
additional operations on the keyboard.

- Press the ⚙ Settings key to access
settings, including these instructions.

##### Fractions

You can perform calculations using fractions with the
ˣ⁄y key.

- Type the fraction with the numerator (top number) followed by
the denominator (bottom number).

1 ˣ⁄y
3 gives: ⅓ ◔

- To add another fraction, use the operator keys and add the next
fraction:

1 ˣ⁄y
3 +
1 ˣ⁄y
2 gives: ⅓ ◔ + ½ ◑ = ⅚ ◕

- To enter a mixed fraction, use the fraction key again:

2 ˣ⁄y
3 ˣ⁄y
4 gives: 2 ¾ 2◕

##### Time durations

You can perform calculations in hours, minutes, and seconds using
the Hrs and
min keys.

- For example, to calculate the duration of eight lots of twenty
minutes:

8 ×
2 0
min gives: 8 × 0:20 = 2:40

- To enter a value in seconds, enter 0 minutes with the
min key, then the seconds. For example,
for thirty seconds:

0 min
30 gives: 0:00:30

- For example, if a heart beats twenty-three times in fifteen
second, then the heart rate in beats per minute can be calculated
as:

2 3
÷ 0
min 1
5 gives: 23 ÷ 0:00:15 = 115

##### Time with the clock

To perform calculations using clock time, you also use the
⏱ key.

- To enter a time in the morning (a.m.), press the
⏱ once:

8 ⏱ gives: 8:00
a.m. ⏲

- To enter a time in the evening (p.m.), press the
⏱ twice:

8 ⏱
⏱ gives: 8:00 p.m. ⏲

- To calculate four and a half hours after eleven o'clock at
night:

1 1
⏱ ⏱
+ 4
Hrs 3
0 gives: 11:00 pm ⏲ + 4:30 = 3:30 am (+1
day) ⏲

##### Percent and tax

You can perform calculations with percentages using the
% key.

- For example, to add five percent to thirty:

3 0
+ 5
% gives: 30 + 5% = 31.5

- To find eight percent of forty:

8 %
× 4
0 gives: 8% × 40 = 3.2

The Tax key can be used to calculate pre-
and post-tax amounts.

- Configure the tax amount in the
⚙ *Settings* dialog.

- To add tax to a $200 pre-tax amount:

2 0 0
+ Tax gives: 200
+ Tax 15% = 230

- To remove tax from a $230 after-tax amount:

2 3
0 -
Tax gives: 230 -
Tax 15% = 200

#### Features

DysCalculator has been designed to support learners with
neurodiverse needs and offers a range of features.

- Logical arrangements with numbers ordered by their magnitude,
from 0 to 9.

0 1
2 3
4 5
6 7
8 9

- Operators arranged according to precedence, following the PEMDAS
(also known as BODMAS) rule: parentheses (brackets), exponents
(orders, powers, roots), division / multiplication and addition /
subtraction.

1 + 2 × 3 = 7

- Natural-order entry for unary and binary operators.

sin ( 45 ) = 0.707

3 √ 8 = 2

10ˣ 3 = 1,000

##### Expressive display

- Formula field that shows the entire calculation with real-time
evaluation.

1 + 2 = 3

- Optional visual cues in the display area grouping parenthetical
sub-expressions.

3 ^ (1 + 2) = 27

- Thousands separator.

1,200,300.456789

- Expressive display of fractions and time.

½ ◔ + ⅓ ◔ = ⅚ ◔

9:45 pm ⏲ + 6:30 = 4:15 am ⏲ (+1 day)

- Percentages are calculated using idiomatic phraseology.

150 + 10% = 165

- Calculate pre-tax net amounts for gross cost.

230 - Tax 15% = 200

- Trigonometric functions can work in degrees or radians.

sin(90) = 1

sin(π ÷ 2) = 1

##### Customisation

Optional customisations in DysCalculator:

- Greeting, customisable to user's name.

- User-selected alternate key labels, such as "plus" and "and" for
addition key.

- Irlen shading to improve legibility of keys and values.

- OpenDyslexic font to assist learners with dyslexia.

- Multiple language support including Te Reo Māori.

#### About

DysCalculator is the culmination of many years work helping to
improve maths accessibility for learners with dyscalculia. Its
design has been tested with numerous users. It aims to remove
complexity from tasks involving maths by understanding and
anticipating how the user uses the technology. ## Contributors

- Gary Sharpe: Dyscalculia expert and designer.

- Philip Schlup: Software developer and algorithm designer.

- Michael Grawe: Project manager and marketing coordinator.

#### Contact