Which statements about solving the problem (0.1 x 5) + 0.4 are true? Check all that apply. Using a calculator will be much more efficient to solve the problem because there are multiple decimal operations to perform. All of the calculations can be done quickly by hand, so using a calculator will be less efficient. The first calculation cannot be done quickly by hand, so using a calculator will be more efficient. If a calculator is going to be used, it is a good idea to compare it to an estimate of the actual calculation done by hand. Using a calculator or solving the problem by hand can both result in the correct answer.