Calculation Triangle vs Mambio

Three fields inside, three numbers outside: each outer number is the sum of the two fields next to it. The calculation triangle (Rechendreieck) is a well-known exercise format in primary school mathematics – this app turns it into a virtual manipulative. Children place counters in the fields, and the outer numbers change with every move. The app is in German. The first version appeared in 2012. The new edition is an open environment for exploring mathematics in primary school. LESS IS MORE At the start the triangle looks like the original: counters inside, numbers outside, nothing else. Everything else is tucked away in the buttons and settings – or an investigation card brings it along. The reduced view shows only the triangle and the gear button, similar to the first version. WITH ALL FINGERS • Tap to place a counter, with several fingers at once to place several • Drag counters to another field • Drag them out to remove them, shake to clear the triangle FOUR REPRESENTATIONS Counters only, counters with numbers outside as in 2012, counters and numbers, or numbers only. All representations are linked: children move from the material to the numbers and back. COVER AND GUESS A shutter covers a field, outer numbers can be hidden. To uncover, children first enter their guess. Every triangle becomes a task of working things out. TASKS AND INVERSE TASKS The dice sets basic tasks (inside given), mixed tasks and inverse tasks (outside given), with addition or multiplication, up to 10, 20, 100, 1000 or a custom limit. In free mode, children enter all numbers themselves and check their triangle. Unsolvable inverse tasks can be switched on – then an explanation is needed. WRITE LIKE IN AN EXERCISE BOOK From number range 20, children write their guess under the shutter with a finger or pencil into boxes. Recognition runs on the device; a button switches to the keypad at any time. 33 INVESTIGATION CARDS For grades 1 to 4: find all possibilities, work out hidden counters, change tasks and observe what happens to the outer numbers, explain whether something always works. Most cards end with a question asking for an explanation, eleven show a short video. A speaker button reads the card aloud, and a word bank with key terms and sentence starters helps children explain. NO POINTS, NO STARS No time pressure and no grading: children check for themselves whether their triangle is correct. FOR SCHOOL • Introductory videos for children and for teachers • Equations for the triangle, optionally with inner and outer sum • Collection: save triangles, compare them and print them as a worksheet • Link and QR code for a prepared triangle on all devices in class • Read-aloud for children who cannot yet read confidently • Sharing, printing and the activity log are behind a multiplication task for adults PRIVACY • No ads • No tracking • No in-app purchases • No registration • No internet connection needed • All data stays on the device Developed by Christian Urff, mathematics educator and developer of virtual manipulatives for primary school mathematics.

Mambio is the child-friendly math app that lets your child learn mathematics playfully and independently – completely free of subscriptions and ads! With scientifically grounded learning methods and individual tasks in colorful learning worlds, math becomes exciting and motivating. Try for free: • Counting to 10 with Mambi and his crew. • Digital quantity field for practicing at school or at home. • Find out whether grouping by 2s or 5s works best for your child. Extended packages (one-time in-app purchase): "Learning up to 20" package • Your child learns to count and calculate up to 20 with Mambi. • Varied adventures in the fairy, monster, and dinosaur worlds keep your child's attention engaged. • Tasks on number sense, mental addition, and subtraction. • Learning statistics in a PIN-protected area to track progress. "Learning up to 100" package • Your child practices all four basic arithmetic operations with numbers up to 100. • Exciting learning adventures in the fairy, monster, and dinosaur worlds keep motivation high. • Explainer adventures for addition, subtraction, multiplication, and division. • Learning statistics to track learning success. Why Mambio? • No subscription, no ads: Buy once and use forever. • Individually tailored: Scientifically developed learning content supports your child individually. • For all children: Suitable from age 5 and for every learning pace. Mambio promotes sustainable learning without a reward system and helps your child master mathematics independently! https://www.apple.com/legal/internet-services/itunes/dev/stdeula/