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Math K-Plus

Arithmetic - Summary Of Multiplication Lessons And Calculators For First Grade, Second Grade, Third Grade, and Fourth Grade

SECOND GRADE EXAMPLE: MULTIPLY TWO NUMBERS




Problem: Multiply Two Positive Integer Numbers.



     +57
   × +13
  ——————


      57
   ×  13
  ——————


Multiply the number on row 1 column 1 (3)
with the number on row 2 column 1 (7).
The product is (3 × 7) = 21.
Move 1 of 21 to column 1 of the answer line.
Carry 2 of 21 to column 2.



      2
      57
   ×  13
  ——————
       1




Multiply the number on row 1 column 1 (3)
with the number on row 2 column 2 (5).
The product plus the carry is (3 × 5) + 2 = 17.
Move 7 of 17 to column 2 to the answer line.
Carry 1 of 17 to column 3.



     12 
      57
   ×  13
  ——————
      71




        
      57
   ×  13
  ——————
     171




Multiply the number on row 1 column 2 (1)
with the number on row 2 column 1 (7).
The product is (1 × 7) = 7.
Move 7 of 7 to column 2 of the answer line.



        
      57
   ×  13
  ——————
     171
      7




Multiply the number on row 1 column 2 (1)
with the number on row 2 column 2 (5).
The product is (1 × 5) = 5.
Move 5 of 5 to column 2 of the answer line.



        
      57
   ×  13
  ——————
     171
     57 




        
      57
   ×  13
  ——————
     171
     57 




Problem Solution - Sum each answer line to get complete anwser:




        
      57
   ×  13
  ——————
     171
     57 
  ——————
    +741


Let's compute the answer by summing each result.
171 × 1 = 171
57 × 10 = 570



SUM OF MULTIPLICATIONS: 741