26/09/2013 Using Fingers to Count and Multiply

During yesterday's lesson, we worked on multiplication and division. 

Although the problems are more complicating, I observed that all the basic concept of math were continuously used. We were constantly looking out for patterns and counting. We were also constantly exploring possible ways to get the answers. As we explored, we found ways which worked like magic! :P

These so-called tricks help us to understand math better and is very different from memorizing without understanding hands on. Memorizing is robbing children of the opportunity to learn. It is fascinating to find new ways which works and help us count and multiply faster.

Below is a video of a boy counting( addition and subtraction) using just a finger trick he learned.

Can you identify which finger is the special number?

I just learned a faster way to count from a 5 year old!^.^

I also found another amazing way to multiply numbers 6,7,8,9 and 10 using fingers!

obtained from this website: Finger Multiplication of 6,7,8,9,10

Place your fingers as in the below image and consider the value of fingers in each hand to be 6, 7, 8, 9 and 10 - in the order from small finger to thumb. Example Consider the multiplication of 7 × 8. Make the finger numbered 7 in the left hand to touch the finger numbered 8 in the right hand. Step 1: Now in the left hand, count the finger which is touching (7) and the ones below that = 2 fingers Similarly in the right hand, count the finger which is touching (8) and the ones below that = 3 fingers Add the above counted fingers = 2 + 3 = 5 fingers Multiply the number by 10 = 5 × 10 = 50 -----> (1) Step 2: In the left hand, count the fingers above the touching finger = 3 fingers Similarly in the right hand, count the fingers above the touching finger = 2 fingers Multiply both = 3 × 2 = 6 -----> (2) Step 3: Add (1) and (2), = 50 + 6 = 56 So, the answer for 7 × 8 = 56 which is easily found through the above trick. Note: If there is no finger above the considered (touched) finger, then consider the value as zero (0). Play the same for the below multiplications 6 × 6 = ? 6 × 7 = ? 6 × 8 = ? 6 × 9 = ? 6 × 10 = ? 7 × 6 = ? 7 × 7 = ? 7 × 8 = ? 7 × 9 = ? 7 × 10 = ? 8 × 6 = ? 8 × 7 = ? 8 × 8 = ? 8 × 9 = ? 8 × 10 = ? 9 × 6 = ? 9 × 7 = ? 9 × 8 = ? 9 × 9 = ? 9 × 10 = ? 10 × 6 = ? 10 × 7 = ? 10 × 8 = ? 10 × 9 = ? 10 × 10 = ?

And of course, we have the ingenious finger trick of the multiplication of 9.