Hadley tried to evaluate $5\times4000$ step by step. $$ | $\phantom{=}\greenD5\times\blueD{4000}$ - | - ${\text{Step } 1}$ | $=\greenD5 \times \blueD{4} \times \blueD{1000} $ ${\text{Step } 2}$ | $= 20\times \blueD{1000} $ ${\text{Step } 3}$ |$=20{,}000$ **Find Hadley's mistake.** [[☃ radio 1]]