Multiply Multi-Digit Whole Numbers Practice Test

A school is ordering new textbooks. They need $$147$$ books for each of their $$23$$ classrooms. Each book costs $$\28$$. What is the total amount the school will spend on textbooks?

Roberto multiplies $$234 \times 67$$ and gets $$15678$$. To check his work, he decides to use the fact that $$67 = 70 - 3$$. Which expression should Roberto calculate to verify his answer?