Big Math vs Keywords Understanding Lite
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Big Math
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Big Math is an iPad app for elementary school children to practice addition, subtraction, multiplication and division of big numbers. It has both portrait and landscape orientation. It has a dolphin theme, and when the child has finished a set of problems, a dolphin sound (whistle, scream, yell or motorbike) is heard. The child starts by picking what he or she wants to work on in the Settings screen of the app. Settings options include: * Entering a name and message for the child who will be using the app. The name and message show up throughout the app. * Entering the options for addition, subtraction, multiplication, and/or division. For addition, the child can add 2 numbers, either 2 digit or 3 digit, or 3 numbers, either 2 digit or 3 digit. For subtraction, the child can subtract either 2 digit or 3 digit numbers. For multiplication, the child can multiply 2 digit or three digit numbers. For division (long division), the child can divide with a 1 digit, 2 digit, or 3 digit divisor. The app allows regrouping, where the child can "carry" in addition, multiplication, and division or "borrow" in subtraction and division. The child can elect to have problem sets timed. Once the settings are set, the child goes to the area he or she wants to practice (Big Add, Big Subtract, Big Multiply, or Big Divide), selects the number of problems to do, and starts doing Big Math! Dolphin sounds are courtesy of Dolphin Encounters in the Bahamas! Try it and enjoy!
Keywords Understanding Lite
This app offers a sample of speech and language therapy exercises focused on sentence comprehension. It helps users practice following directions, understanding basic concepts, and improving auditory and reading comprehension skills through interactive activities.
- Listening comprehension exercises
- Reading comprehension exercises
- Following directions (one/two-step, temporal, sequential)
- Basic concepts (size, color)
- Vocabulary understanding
- Sample of full app features
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Keywords Understanding LITE is a free version of Keyword Understanding. It gives you a sample of the content you would get in the full version. It allows you to see how the full version works and try it out for free. Keyword Understanding (the full app version) is a professional speech and language therapy app that works on sentence-level reading and listening comprehension. It also targets the understanding of vocabulary, basic concepts and the ability to follow directions of increasing keyword length. WHO IS KEYWORD UNDERSTANDING FOR? - Children with reduced attention and auditory processing difficulties - Children with language delay or disorder - Children with autism and language comprehension difficulties - Adults with aphasia and reading or spoken language comprehension difficulties after a stroke or traumatic brain injury - Adults with cognitive-communication difficulties due to stroke or brain injury WHAT LANGUAGE AREAS DOES KEYWORD UNDERSTANDING TARGET? FOLLOWING DIRECTIONS: Following directions is important in our everyday lives. In order to understand and follow directions, one needs a strong knowledge of basic concepts, vocabulary and the ability to process and retain spoken or written information in memory. BASIC CONCEPTS, ONE AND TWO STEP DIRECTIONS: Keyword Understanding works on the basic concepts of size and color as well as one and two-step directions of increasing length and difficulty e.g - “Touch the red balloon” - “Touch the small green umbrella” - “Touch the yellow chair and the blue candle” - “Touch the big pink cupcake and the small green glasses”. TEMPORAL DIRECTIONS (BEFORE/AFTER): Keyword Understanding includes Temporal Directions tasks that target the child or adult’s ability to follow directions that include the concepts 'Before/After' in a variety of positions in the sentence. e.g - “Before you touch the t-shirt, touch the phone” - “After you touch the lamp, touch the vase” - “Touch the flower before you touch the box” - “Touch the sock after you touch the bucket” SEQUENTIAL DIRECTIONS (FIRST…THEN): The app also includes Sequential Directions that target the child or adult’s ability to follow directions that include the concepts 'First ... Then' in the sentence. e.g - “First touch the ladder, then touch the bike”. FEATURES OF KEYWORDS UNDERSTANDING LITE This FREE version, Keywords Understanding LITE allows you to sample each activity in the full version but it only includes 6 objects. The FULL version includes many more allowing for much more variety in each activity and many more trials. The full version also allows you to select and deselect vocabulary items in the Word List. 3 modes: - Listening Comprehension (Audio Only): Match the spoken direction to the pictures - Reading Comprehension (Text Only): Match the written direction to the pictures - Listening and Reading Comprehension (Audio and Text): Match the spoken and written directions to the pictures - Bright, colorful, real-life photos of common objects - 6 objects in five different colors and sizes. The full version has a large variety allowing for thousands of possible following directions tasks - 3 trials in each activity. The full version allows for up to 50 trials per session. - A comprehension check activity to find out where comprehension breakdown occurs - Audio feedback for correct answers only, incorrect answers only or both - Graded tasks of increasing difficulty - User profiles and result history - Automatic tracking of scores - Optional results summary via email - iOS voices (automatically selected based on your region). Download an enhanced iOS voice for best quality. All Aptus Speech Therapy apps participate in the 50% off Volume Purchase Program, so you can buy in bulk at a discounted price. Are you looking for a different kind of speech therapy app? Check out our full range of speech and language therapy apps for adults and children on the AppStore or on our website.
Screenshots
Verdict
The clearest difference is price: Keywords Understanding Lite at Free against Big Math's $1.99. Keywords Understanding Lite also leads on device support (3 vs 1). Big Math's advantage is update cadence (every 11 months vs every 68 months). On ads, in-app purchases and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Keywords Understanding Lite is free to download; Big Math costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Big Math ships an update every 11 months, Keywords Understanding Lite every 68 months. The most recent releases landed on November 10, 2026 and November 3, 2026 respectively.
| Parameter | Big Math | Keywords Understanding Lite |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | — | 5.0 (3 ratings) — better |
| Number of ratings | — | 3 — better |
| Update frequency | Every 11 months — better | Every 68 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPad | iPhone, iPad, iPod — better |
| Requires iOS | 15.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 18 MB | 60 MB |
| Age rating | 4+ | 4+ |
| Developer | Eaglet LLC | Aptus Speech and Language Therapy Limited |
In-app purchases
Big Math
No in-app purchases
Keywords Understanding Lite
No in-app purchases
Questions
Is Big Math free?
Is Keywords Understanding Lite free?
Do Big Math or Keywords Understanding Lite have ads?
Which is updated more often, Big Math or Keywords Understanding Lite?
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