Solve: 0.4 × (3+1) Using Order of Operations

The parentheses tell you what to calculate first! In $0.4 \times (3+1)$, you must solve $(3+1) = 4$ before multiplying by 0.4.

Think of 0.4 as 4 tenths! So $0.4 \times 4$ means 4 tenths × 4 = 16 tenths = 1.6. Or use: $4 \times 4 = 16$, then move decimal one place left.

Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). Always do operations in this order!

Yes! $0.4 \times (3+1)$ is the same as $0.4(3+1)$ or $(3+1) \times 0.4$. The parentheses still come first in all versions.

You probably calculated $0.4 \times 3 + 1 = 1.2 + 1 = 2.2$. But the parentheses change everything! $(3+1) = 4$ first, then $0.4 \times 4 = 1.6$.