Help its the mid chapter checkpoint

Answer:
1. Estimate the quotient helps you place the first digit in a division problem because the estimation is an approximation to the solution of the problem. Take into account that the first digit of the actual solution not necessarily match the first digit of the approximation, but still helps you to find the actual solution because both first digits are near.
2. If you multiply the divisor by the quotient you must obtain the dividend. For example, 210/7 = 30, then 30*7 = 210