Explanation:
A square number (n2) is the result of multiplying an integer by itself (first ten: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100). A cube number (n3) comes from multiplying an integer by itself three times: n × n × n (first five: 1, 8, 27, 64, 125). Never multiply the base by the power (43 ≠ 12).
Roots are the inverse of powers: the square root (√x) asks what positive number squared gives x, and the cube root (∛x) asks what number cubed gives x. Also remember that any non-zero number to the power of 0 equals 1 (x0 = 1).
Example 1: Work out the value of 72 + √81 − 23
Solution:
Evaluate each power or root separately first:
• 72 = 7 × 7 = 49
• √81 = 9 (since 9 × 9 = 81)
• 23 = 2 × 2 × 2 = 8
Combine: 49 + 9 − 8 = Answer: 50
Example 2: Work out the value of 43 − ∛64 + 103
Solution:
Evaluate each term carefully:
• 43 = 4 × 4 × 4 = 64
• ∛64 = 4 (since 4 × 4 × 4 = 64)
• 103 = 10 × 10 × 10 = 1000
Combine: 64 − 4 + 1000 = Answer: 1060