 AbacusFrom the Greek word abax, meaning "calculating board" or "calculating table" the Chinese abacus was invented during the Yuan Dynasty, 1280-1368 AD. The abacus is often referred to as the first computer. This brightly colored wooden abacus is a great first calculator for kids to learn counting, patterns, colors, and more! The hundred colored wooden beads slide smoothly on this classically styled high quality frame. A great value!To use to teach children to add: Each row of the abacus can be used as a number column (ie, ones column, tens column, hundreds column and so on). To add two numbers let's use the example of adding 5 + 4. On the bottom row move 5 beads to the right side and then add another 4 beads to that side. Now count all the beads on the right side. It shows that 5 + 4 = 9. All of the beads on the bottom row are counted as one each. For older children try adding 9 + 6. This introduces the idea of double digits and possibly their first introduction into the "ones" and "tens" columns concept. Take 9 beads from the bottom row and move it to the right. Now to add an additional 6 beads a new rule is introduced. Any time ten beads in one row is used up (all to the right), the next highest row moves 1 bead to the right. Therefore, once 10 yellow beads are over to the right, 1 green bead is moved over to the right on the second row. That makes 1 in the "tens" column. Continue moving the "ones" beads until you have 5 "ones" beads and 1 "tens" beads. The total is 15. Next try adding 10 + 20. This will involve only the "tens" row. Each bead on the second row is worth 10. Therefore, moving 1 bead in the second row to the right equals 10. Moving 2 more beads to the right makes the total of those 3 beads 30. Therefore, 10 + 20 = 30. Now try adding 10 + 11 or 9 + 21. See how it works? Amazing, isn't it! To see other Melissa and Doug items Click here. |
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