Michelle uses 5 2/6 feet of wire and 4/9 feet of plywood for a project if each of her 2 children make their own how many total feet of material will she need

In order to make the math easier, I will convert the mixed number into a fraction:
5  becomes 

Adding fractions is only possible if the denominator, or the bottom number, of each fraction is the same. We can achieve this by multiplying by 3, and  by 2



Then you add the top values and get the following fraction:


Simplifying the fraction gives us:


Then we convert the fraction back into a mixed number, which gives you the final answer of:
5

45 is the only number in both sets