# Arrays and Expanded Algorithm EQ: How can arrays help you multiply 2 digit numbers?

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Arrays and Expanded Algorithm EQ: How can arrays help you multiply 2 digit numbers?

Multiply Using an Array There are 13 bobble head dogs in each row of the carnival booth. There are 24 equal rows. How many dogs are there? Use R.I.F.F.S to assist you. Draw an array for 24 x 13 Separate each factor into tens and ones. (write in expanded form) (20 + 4) x 10 Use the distributive property to solve. (20 + 4) x 3 Use the distributive property to solve. Find the number of squares in each rectangle. 20 10 4 20 3 4 3 200 40 60 12 Add the partial products 200 60 40 + 12 21 1 3 20 x 10 + 4 x 10 20 x 3 + 4 x 3

26 x 24 Checklist  Write factors in expanded form (separate tens and ones)  (20 + 6) x 20 and (20 +6) x 4  Use the distributive property  20 x 20 20 x 6  20 x 4 6 x 4  Add all partial products  Circle your answer 400 120 80 24 400 120 80 + 24_ 42 1 6

12 x 14 Checklist  Write factors in expanded form (separate tens and ones)  Use the distributive property  Add all partial products  Circle your answer 100 20 40 8 100 20 40 + 8_ 168

18 x 26 Checklist  Write factors in expanded form (separate tens and ones)  Use the distributive property  Add all partial products  Circle your answer 200160 6048 200 160 60 + 48_ 468 1