One way to transform an equation is by breaking up the numbers into smaller parts.Using parentheses and addition, we can split a number into two or more addends.
For example, with 9 × 7, we can split 9 into 5 + 4 and 7 into 4 + 3. Then we can write the equation as (5 + 4) × (4 + 3).
Since the numbers in the parentheses are being added together, you can also switch their order: (4 + 5) x (3 x 4).
Also, because multiplication is commutative, the order of the parenthetical expressions can be switched: (3 x 4) x (4 + 5).
This works because parentheses tell us to add the numbers inside first, and then multiply. That’s why breaking numbers into sums still gives the same result as the original multiplication.
