Question

Andrew was making a science project for school he worked for 6.6 hours The first week 2.75 hours the second week and 4.4 hours the third week Andrew used the following mental math strategy to find the total number of hours he worked on his project what is the reason for his strategy A it is easier to add decimals in a decreasing order then in a mix order B 6.6 and 4.4 are Compatible numbers that are easy to add mentally C it is easier to add decimals with the same number of place value after the decimal point then adding decimals with different numbers of place value after the decimal point D rounding removes the decimal and creates whole number

Answer 1

To determine which option best explains Andrew's mental math strategy when adding the hours he worked, we should analyze the choices:

A. It is easier to add decimals in a decreasing order than in a mixed order.

• This could be true as some might find it easier to add larger numbers first, but it is not a strong reason related to mental math.

B. 6.6 and 4.4 are compatible numbers that are easy to add mentally.

• This is true; 6.6 and 4.4 are both simple decimal numbers that can be easily added together.

C. It is easier to add decimals with the same number of place value after the decimal point than adding decimals with different numbers of place value after the decimal point.

• While this statement is accurate, it isn't specifically applicable to the numbers Andrew worked with.

D. Rounding removes the decimal and creates whole numbers.

• This is a technique often used in mental math but doesn't apply directly to how Andrew approached the addition of the specific decimal values he had.

Given these analyses, the best answer regarding the reasoning for Andrew's strategy is:

B. 6.6 and 4.4 are compatible numbers that are easy to add mentally.

This option highlights the simplicity of the numbers involved, making them easier to work with mentally.