Use the hundreds chart to help you identify the number that is 1 more, 1 less, 10 more and 10 less

If a and b are the measures of two first quadrant angles and sin a = 4/9 and sin b = 2/5 find sin(a+b).

You have 6 dollars +12 pennies +to quarters + 4 dimes=2 nickels how much do you have

In two or more complete sentences describe how to determine the appropriate model for the set of data, (1,1), (3,2), (6,3), (11,4).