Question

in the following problems, separate the rows or columns with horizontal or vertical lines.

1. draw an array of xs with 3 rows of 3.

3 rows of 3 =

1. draw an array of xs with 2 more rows of 3 than the array in problem 3. write a repeated addition equation to find the total number of xs.
2. draw an array of xs with 1 less column than the array in problem 4. write a repeated addition equation to find the total number of xs.

Explanation:

Step1: Create 3 rows of 3 X's

X X X
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X X X
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X X X

Step2: Calculate total rows for Problem 4

Original rows: 3, add 2 rows. $3 + 2 = 5$ rows of 3 X's.

X X X
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X X X
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X X X
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X X X
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X X X

Repeated addition: $3 + 3 + 3 + 3 + 3$

Step3: Adjust columns for Problem 5

Original columns: 3, subtract 1 column. $3 - 1 = 2$ columns, keep 5 rows.

X X
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X X
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X X
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X X
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X X

Repeated addition: $2 + 2 + 2 + 2 + 2$

Step4: Compute totals

Problem3: $3+3+3=9$; Problem4: $3×5=15$; Problem5: $2×5=10$

Answer:

Problem 3 Array:

X X X
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X X X
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X X X

Total X's: 9

Problem 4 Array:

X X X
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X X X
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X X X
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X X X
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X X X

Repeated Addition: $3 + 3 + 3 + 3 + 3 = 15$
Total X's: 15

Problem 5 Array:

X X
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X X
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X X
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X X
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X X

Repeated Addition: $2 + 2 + 2 + 2 + 2 = 10$
Total X's: 10