## Addition and Subtraction Maths Tricks

Determine the value of

3+8+6+2+17+3+5+1+2+4

The easiest way of calculating it is rearranging the order in this way:

3+8+6+2+17+3+5+1+2+4 = 3+17+8+2+6+4+3+5+2+1 = 20+10+10+10+1

**Multiplying by 6**

If you multiply 6 by an even number, the answer will end with the same digit. The number in the ten's place will be half of the number in the one's place.

Example:

6 x 4 = 24.

6 x 6= 36

6 x 8= 48

6 x 12 = 72

This is a quick way to multiply two-digit numbers by 11 in your head.

**multiply two-digit numbers by 11 **

This is a quick way to multiply two-digit numbers by 11 in your head.- Separate the two digits in your mind.
- Add the two digits together.
- Place the number from Step 2 between the two digits. If the number from Step 2 is greater than 9, put the one's digit in the space and carry the ten's digit.

Examples: 72 x 11 = 792.

57 x 11 = 5 _ 7, but 5 + 7 = 12, so put 2 in the space and add the 1 to the 5 to get 627

**Multiply a Number by 5**

Even Number

3464 x 5 = ?

step1.

divide it with 2

3464/2 = 1732

step2.

add 0 in the end

answer will be = 17320

Odd Number

3777 x 5 = ?

step1.

odd number - 1 (3777-1)= 3776

step2. divide by 2

3776/2 = 1888

step3. as it is an odd number so instead of 0 we will put 5 in the end

the answer will be 18885

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