Mental Abacus Exercises

20 Aug 2012 (Mon):

After 2 lessons of mental abacus the kids attended, Mummy here have also learned what they've learnt & like to share with you. Of cos u all may have known much more & I am just startng with the very basic.

This is the book they used for lessons in class & as given homework.

The exercises in this book double up as a mock test in class, usually done during the next lesson.

This the abacus plate ( or whatever its call) they used.

The upper row/section of beads represent the number 5.

The lower row/section of beads represent the number 1 ~ 4 beads in 1 column.

See where the red arrow is pointing? They start the calculation from this column. I'm not sure what are the rest of the columns for... maybe for 2 digits or 3 digits calculation... will come to that.

Examples of some of the exercises that they did.

Look at the pink highlighted box:  4 - 4 + 4 = 4...mental calculation is easy..will give u 4 right?

But to do the working on the abacus, how would u calculate?

Note: make sure all beads are pushed down.

Solution: top number is + four, so u got to use ur thumb to push up all 4 beads at the bottom row/section.

middle number is - 4, so u got to use your index finger to push back down all 4 beads.

bottom number is again + 4, so u use your thumb to push up all 4 beads again..

so how many beads u have in total on the bottom row???

Answer: 4

Confused? let's do another sum.

Look at the green highighted box next: 3 - 3 + 2 = 2

Solution: top number is 3, so u use ur thumb to push up 3 beads

middle number is - 3, so u use ur index finger to push back down all 3 beads

bottom number is + 2, so what do u think? Yes, use ur thumb to push up 2 beads..

Answer: 2

You got it?.. Good!

One more time..

Look at the blue highlighted box: 4 + 5 - 3 = ???

Solution: thumb to push up 4 beads... yup

now the middle is 5, so u got to look at the top row/section of the abacus plate

for that, u only use your index finger to do the sums, whether its + or -

so using ur index finger, push up that one bead on the top row/section...

bottom number is - 3, so using ur index finger, push back down 3 beads on the lower row/section of the abacus plate..

Answer: 6 ( that one bead represents 5, remember?) + the remaining 1 bead on the lower section since u have already + 4  and u - 3 again)

Now, we look at the red highlighted one.. 1 + 5 - 5 = ???

You do the sums & let me know... no cheating ya... use the abacus method.. answer will be revealed after the video.

This is a video of the kids doing their exercises. I purposely asked them to read aloud, so that u will know how the working goes...

So did u get ur last question working/answer correct?

Solution: 1 + 5 - 5 = ???

pushed down all ur beads? Okay, let's go

top number is 1, so u use ur thumb to push up... 1 bead.
middle number  is + 5, so u gotta... ( remember u gt to look for 5 at the top row/section of the abacus plate)... what do u do? Good. Using ur index finger, push that 1 bead up.
bottom number is - 5... so dun look away... stay at the top row/section of the plate... what do u do for - 5?
using ur index finger, push down that bead again right?

so what u left on the plate? How many beads u see? U get 1? Excellent.

 i'm only using my own words to guide u along... not professionaly done ya.... hehe.