Math

Chapter 6: Multiply by Two-Digit Numbers

Multiply using an Area Model or the Method FOIL

Break Apart Numbers to Multiply: FOIL

FIRST, OUTER, INNER, LAST

Break each factor into tens and ones --------  78 x 27

• Multiply the first number in each factor       (70 + 8) x (20 + 7) 70 x 20 = 1,400

• Multiply the outer number in each factor (70 + 8) x (20 + 7) 70 x  7  = 490

• Multiply the inner number in each factor (70 x 8) x (20 x 7) 8 x 20 = 160

• Multiply the Last number in each factor (70 x 8) x (20 x 7) 8 x 7   = 56

Add all the partial products together ------- 1,400, 490, 160, 56  =  2,106