To determine which statement is not true, let's analyze each option.
-
2 × 10^6 is 10 times as great as 2 × 10^5:
- \(2 \times 10^6 = 2,000,000\)
- \(2 \times 10^5 = 200,000\)
- \(2 \times 10^6\) is indeed \(10\) times \(2 \times 10^5\) (since \(2,000,000 \div 200,000 = 10\)).
- True
-
4 × 10^8 is 100 times as great as 4 × 10^6:
- \(4 \times 10^8 = 400,000,000\)
- \(4 \times 10^6 = 4,000,000\)
- \(4 \times 10^8\) is indeed \(100\) times \(4 \times 10^6\) (since \(400,000,000 \div 4,000,000 = 100\)).
- True
-
7 × 10^−2 is 1,000 times as great as 7 × 10^−6:
- \(7 \times 10^{-2} = 0.07\)
- \(7 \times 10^{-6} = 0.000007\)
- \(7 \times 10^{-2}\) is not \(1,000\) times \(7 \times 10^{-6}\) (since \(0.07 \div 0.000007 = 10,000\)).
- False
-
9 × 10^−4 is 1,000 times as great as 9 × 10^−7:
- \(9 \times 10^{-4} = 0.0009\)
- \(9 \times 10^{-7} = 0.0000009\)
- \(9 \times 10^{-4}\) is indeed \(1,000\) times \(9 \times 10^{-7}\) (since \(0.0009 \div 0.0000009 = 1,000\)).
- True
Therefore, the statement that is not true is:
7 × 10^−2 is 1,000 times as great as 7 × 10^−6 (this is false).