Regroup 1 one as 10 tenths, then subtract.<br><br>
• 4.5 = 3 ones + 15 tenths<br>
• 3.6 = 3 ones + 6 tenths<br>
• Ones: 3 − 3 = 0<br>
• Tenths: 15 − 6 = 9<br>
• 4.5 − 3.6 = 0.9<br><br>
Final Answer: 0.9