Add and subtract mixed numbers word problems

Stories turn mixed numbers into real amounts, so the unit travels with the answer. Maria's potatoes are pounds, Katy's milk is cups, Miss Edith's fabric is yards, and an answer without its unit is only half finished.

The page also trains the habit of reading what is asked. Maria and Katy combine two amounts, while Miss Edith's question, how many more yards of purple fabric, is a comparison and calls for subtraction. Denominators differ in every story, from halves and fourths to ninths and fifths, so a common denominator comes before any arithmetic.

The standard is 5.NF.A.2, solving word problems that add and subtract fractions of the same whole with unlike denominators.

Let your child read Katy's problem aloud and pause at the comma. "Is the 5 7/15 cups for the cake or the icing?" It goes into the flour mixture; the 2 1/2 cups make the buttercream, and both count as milk.

The common slip on this page is forgetting to turn the improper fraction back into a mixed number: 239/30 is correct but unfinished, and the instructions ask for 7 29/30. Ask, "How many whole cups fit in 239/30?"

A note for parents on problem 1: the worked answer writes 55/4 in the middle, but 6 1/2 + 7 3/4 is 57/4. The final 14 1/4 pounds is right. Problem 3 is labeled Addition although it is a subtraction; 1 1/45 yards is correct.

Shopping gives this skill a second life. At the grocery store, weigh two bags of apples, say 2 1/4 and 1 3/4 pounds, and have your child add them before the scale does.

At home, a tape measure and a strip of ribbon turn Miss Edith's question into a real one: how much longer is 2 1/2 yards than 1 3/4 yards?

Spaghetti and Meatballs for All! by Marilyn Burns follows a family reunion dinner where the guests keep rearranging the tables, a reminder that plans and amounts change as a story unfolds.

Recognize the persistence: "You kept the unit in every answer, all the way through." Estimating sums and differences of mixed numbers is the next sheet.