Ripley told his mom that multiplying whole numbers by multiples of 10 was easy because you just count zeros in the factors and put them in the product. He used these two examples to explain his strategy.

7,000 × 600 = 4,200,000
(3 zeros) (2 zeros) (5 zeros)

800 × 700 = 560,000
(2 zeros) (2 zeros) (4 zeros)

Ripley’s mom said his strategy will not always work. Why not? Give an example.