Xyla and Yabu 4+

Number Bond Bars to 20, to 100

Karen McDonald

Designed for iPad

    • $0.99

iPad Screenshots


Explore number bonds for numbers to 20 and to 100 by trading gems with Xyla and Yabu!

Help Xyla and Yabu trade gems back and forth by learning to add and subtract with number bonds. Use the relative sizes of number bond bars representing parts and wholes to develop number sense while solving word problems. Understand and become automatic at using tens, doubles, and other recurring patterns with numbers.

Each number bond is presented in the context of a problem that Xyla and Yabu pose for themselves. After mastering sums up to 20 (14 activities), kids explore similar patterns with sums up to 100 (13 activities), for 10 levels in all.

The game-like recognition format, in which kids choose the correct answer from three choices, provides immediate feedback in a non-busy environment conducive to thoughtful exploration.


•Number bonds present addition and subtraction facts simultaneously in terms of parts and wholes.
•Sizes of bars in number bonds show the relative sizes of quantities.
•Story format with characters Xyla and Yabu provides context for word problems.
•Activities increase in difficulty, starting with sums up to 5 and gradually increasing to sums up to 100.
•Patterns include: Counting On (+1 and +2), Doubles, Doubles +1, Making Tens, and Using Tens to make larger sums.
•Missing number activities, most with picture or bar hints, let children start forming foundations for understanding equal expressions in algebra.
•Recognition format, in which kids choose the correct answer from three choices
•Requires only single touches
•Self-contained; children will not see ads and will not have access to in-app purchases or Internet from within this app

Visit the website to download a checklist of activities and suggestions of ways to use this app in a classroom or at home.

What’s New

Version 1.3

Updated for current iOS requirements.

App Privacy

The developer, Karen McDonald, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

You Might Also Like

Solving Multi Step Equations
Finding the Equation of a Line
Teachley Fractions Boost
Flash Card Battle