The Eight Table in Mathematics

The Eight Table in Mathematics




The Eight Table in Mathematics

The 8s table is completely different from the 6s and 7s, but just as easy to learn. Read the entire method before you teach it, because it can be taught either with or without the "8 X 1" math fact.

Let's multiply 8 X 1 as an example.

Tell the student that 8 X 1 is ZERO tens and 8 ones. Explain that if you have your hands in the position shown in Fig. 11, that the thumbs can't reach across the space to touch each other, so that's where we get the zero tens from. This becomes clear as we move through the 8s table.

See Fig. 11:

To multiply 8 X 2, the student places the index, or 2nd fingers (as in the "2" of 8 X 2) together. Not counting the thumbs, the attached index fingers signify one set of 10 and the fingers below are the 1s, which in this case are 6 ones.

See Fig.12:

Going on, to multiply 8 X 3, the student simply places his/her middle fingers together like last time, so now we have two sets of attached fingers ( or 2 sets of 10), the index and middle finger pairs. So, that means there are two 10s, and the remaining "loose" fingers are the ones, which in this case are 4 ones.

See Fig. 13:

8 X 4 would entail joining the ring fingers together (along with the index and middle joined pairs, of course), to have a total of 3 pairs of joined fingers, and the pinkies left over, so you would have 3 tens and 2 ones.

Now.....

When you get to 8 X 5, notice that all the fingers are attached to their mates, so you have four 10s and zero 1s. See Fig. 14:

To continue the pattern, tell the student that since you've run out of fingers, you're going to "reload" by giving the "40" to the thumbs. Thus, 8 X 6 is four tens (remember, the thumbs now have the job of being "40") and 8 ones as in Fig. 15:

To help with the switch from 8 X 5 to 8 X 6, have the student start in the 8 X 5 position and slowly bring the thumbs together. When they touch, release the fingers. Then slowly raise the fingers overhead as in Fig. 15.

Thus, 40 is displayed EITHER as 4 sets of joined fingers OR as a pair of thumbs. The only time when BOTH are displayed is when computing the answer to 8 X 10.

8 X 7 is simply a matter of adding a set of ten to the forty that's contained in the thumbs, and thus you have FIVE 10s and the six remaining "loose" fingers to get 56, and so on.

See Fig. 16:

If the student is aware that any number multiplied by one yields a product of the same number, you can more than likely skip the "8 X 1" step. I have included it here because some students are very literal about mathematics, and appreciate seeing the pattern presented from the outset. Use your own judgment.

Also, you can remind the student that the "loose" fingers are below the thumbs for 8 X 1,2,3,4,5 and above the thumbs for 8 X 6,7,8,9,10. For younger students, the following rhyme seems to help:

"The THUMBS become forty, AFTER 5 X 8
8 fingers OVER forty, 8 X 6 is 48"

John F. Gould
(c) 2000 all rights reserved


or for visual and use right brain....