​1 Digit Sums : Use the 5 formula or 10 formula

​

​ 4 + 6 = +10 - 4 (7+6 = +10-4 = 6 (7+10-4=

​ + 5

​ ---

​ 9 7 + 10 = 17 - 4 = 13

​2 Digit Sums = same

​18 + 49 = 18 = +20 - 2 and 49 = +50 - 1

​

​20 + 50 = 70 - 2 - 1 = -10 + 7 = -3 = 20 + 50 - 3 = 67

​3 digit + 3 digit + 3 digit

​ Ex.

498

​+757

​+985 Ans . 2240

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​

​How to do?

​First add the first 2 two numbers of the digit

​For the example above,

​It is 49 + 75 + 98 = 90 trick = 100 + 75 - 2 = 173 + 50 - 1 (trick) = 222 so now add the ones digit 8 + 7 + 5 = 20

​now add the carry to the tens place so 222 + 2 = 224 and the ones place = 2240 is answer

​4 Digit Trick

​Works as same as the 3 digit trick but Add tens first and then tens \

​Example:

​ 4498

​ + 6826

​ + 1169 Ans . 12493

​ ----------

​

​

​44 + 68 + 11 = 123

​98 + 26 + 69 = 193

​ADD = 123 first 3 digits

​Carry hundred's digit so 124 and then 93 = 12493 answer

​Multiplication Tables Trick From 1 to 10

​ 6 x 8 = half of 8 = 4 (half of 80 = 40 = 8 x 5 = 40 + 8 = 48)

​Examples

​7 x 9 = 7 x 10 = 70 - 7 = 63

​4 x 3 = double of 4 (then add 4)

​4 x 4 = (double + double) double of 4 = 8 + 8 = 16

​9 x 8 = (half + double + single) = 45 + 18 + 9 = 27 + 45 = 72

​

​Multiplication Multipliers

​

​1 = Single 2 = Double 3 = Double + Single 4 = Double + Double 5 = Half

​6 = Half + Single 7 = Half + Double 8 = Half + Double + Single (or Full - Double)

​9 = Half + Double + Double (or Full - Single 10 = Full

​Use these tricks to help you out!