The given numbers from least to greatest are
• 1 - 21 = -20
,
• -0.89
,
• 0.4
,
• 0.5
,
• 9/8 = 1.125
To order the number from least to greatest, we just have to know the value of each one. For example, 1 - 21 equals -20, this will be the least number because it has the greatest absolute value as a negative number. Then, we have -0.89, which is greater than -20. And so on.