DAGDAG-BAWAS (ADD-SUBTRACT)

Dagdag-Bawas is a famous term in Philippine elections. It means Add-Subtract in English. It is also a process used by election cheaters.

Example:

No. Of Voters in a particular precinct:                  390

No. Of Votes obtained by Candidate A:               230

No. Of Votes obtained by Candidate B:               160

Rule: Total number of votes of all candidates should be equal to or should not be more than the total number of voters in a particular precinct.

Total number of Votes obtained:  230+160 =   390

Dagdag-Bawas:

Operator/Supporter for Candidate B conspiring with election personnel cheats by adding 100 to Candidate B’s total and subtracting 100 to Candidate A’s total.

Results reported:

No Of Voters in a particular precinct:                   390

No. Of Votes obtained by Candidate A:               130

No. Of Votes obtained by Candidate B                260

On its face, it’s in order because the total number of votes obtained by both candidates’ equals the number of voters in the precinct. Of course, there was Dagdag-Bawas.

Mental Math – Addition and Subtraction

I gave the above example to show the importance of Arithmetic especially Mental Math even in elections in a democratic country like the Philippines. Elections are about numbers. Politics is not just Addition. It is also Subtraction, Multiplication, and Division. It is therefore an advantage for voters and/or supporters to be proficient in Arithmetic or even better in Mental Math.

ADDITION – Left to Right

Mentally, we normally read numbers from left to right. So, to calculate or add mentally, it is better to process it also from left to right.

Examples:

(a).

                        102

            +          204

            +          451

            +          222

            _________

Answer:        979

Mental Steps:

Step 1: Mentally add the hundreds (100s): 100+200+400+200 = 900

Step 2. Mentally add the tens (10s):                    50+20 =                70

Step 3. Mentally add the single digits: (1s)        2+4+1+2 =             9

Step 4. Mentally say: 900…70…9.                                                979

(b)

                        5120

            +          1235

            +          2423

            +          1221

                        ____ 

Answer         9999

Mental Steps:

Step 1: Mentally add the thousands (1000s): 5000+1000+2000+1000 = 9000

Step 2: Mentally add the hundreds (100s): 100+200+400+200 =              900

Step 3: Mentally add the tens (10s):                    20+30+20+20 =               90

Step 4: Mentally add the single digits (1s):        0+5+3+1 =                           9

Step 5: Mentally say:           9000…900…90…9                                     9999

SUBTRACTION

Subtracting from 1,000

Example:

(a)  1000 – 846 =

Answer: 154

How: To subtract a large number from 1,000 you can use this basic rule: subtract all but the last number from 9, and then subtract the last number from 10:

Step 1: Subtract 8 from 9 = 1

Step 2: Subtract 4 from 9 = 5

Step 3: Subtract 6 from 10 = 4

Answer: 154

Subtracting by Adding instead of borrowing

Example:

(a)  124 – 57 =

Answer: 67

How:

Step 1: 124 – 60 = 64

Step 2:  64 + 3 (60-57) =

Answer:        67

These are just few mental math tricks that I thought would motivate the young to like Math. These tricks actually help sharpen even the mind of the aged too.

I will give more examples in subsequent column/blogs. I will also provide some references to learn more of them.