Split it apart. Keep the total.

SparkClass

Break a multiplication array into two friendlier facts—then join it back together.

CCSS 3.OA.B.5 · 3.MD.C.7c
Live Unit-Square Array
48 squares · joined
A multiplication array split into two smaller arrays Six rows and eight columns of unit squares, split after five columns. The coral array has 30 squares and the teal array has 18 squares, for 48 in all.
Drag the gold divider
01

6 rows × (5 + 3) columns. The 48 squares are grouped as 30 coral squares and 18 teal squares.

Coral Area30square units
+
Teal Area18square units
=
Whole Array48square units

Teacher notes — Split the Array

Let students see the distributive property as a way to reorganize an array, not as a rule made only of symbols.

1

Count the whole first

Ask for the number of rows and columns before moving the divider. Connect rows × columns to the total number of unit squares and to the rectangle’s area.

2

Choose a useful split

Splitting at 5 makes facts such as 6 × 8 easier: 6 × (5 + 3) becomes 6 × 5 + 6 × 3. Ask students to explain why both smaller products use the same number of rows.

3

Separate, then conserve

Use Separate and Join to make the two parts explicit. Ask: “What changed? What stayed the same?” Only the spacing changes; no squares are added, removed, or resized.

CCSS alignment: 3.OA.B.5 — apply properties of operations, including the distributive property. 3.MD.C.7c — use tiling to show that the area of a rectangle with whole-number side lengths is the sum of the areas of its non-overlapping parts.