In your own words explain the place value relationship when the same two digits are next to each other in a multi digit number

Tracy solved the following problem. which of the statements is true? 9 ÷ 3 + 6 × 2 3 + 6 × 2 9 × 2 18 her answer is correct. her answer is incorrect. she should have multiplied before dividing. her answer is incorrect. she should have multiplied before adding. her answer is incorrect. she should have added before dividing.

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?