Common multiplication and division situations shaded

Common multiplication and division situations shaded

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  Common Multiplication andDivision Situations (pg 89 in CCSS) Grade level identification of introduction of problems taken from OA progression Unknown Product Group Size Unknown (“How many in each group?” Division) Number of Groups Unknown (“How many groups?” Division) 3 x 6 = ? 3 x ? = 18; 18 ÷ 3 = ? ? x 6 = 18; 18 ÷ 6 = ? Equal Groups There are 3 bags with 6 plums in each bag. How many plums are there in all? Measurement example. You need 3 lengths of string, each 6 inches long. How much string will you need altogether? If 18 plums are shared equally into 3 bags, then how many plums will be in each bag? Measurement example. You have 18 inches of string, which you will cut into 3 equal pieces. How long will each piece of string be? If 18 plums are to be packed 6 to a bag, then how many bags are needed? Measurement example. You have 18 inches of string, which you will cut into pieces that are 6 inches long. How many pieces of string will you have? Arrays4, Area5 There are 3 rows of apples with 6 apples in each row. How many apples are there? Area example. What is the area of a 3 cm by 6 cm rectangle? If 18 apples are arranged into 3 equal rows, how many apples will be in each row? Area example. A rectangle has area 18 square centimeters. If one side is 3 cm long, how long is a side next to it? If 18 apples are arranged into equal rows of 6 apples, how many rows will there be? Area example. A rectangle has area 18 square centimeters. If one side is 6 cm long, how long is a side next to it? Compare A blue hat costs $6. A red hat costs 3 times as much as the blue hat. How much does the red hat cost? Measurement example. A rubber band is 6 cm long. How long will the rubber band be when it is stretched to be 3 times as long? A red hat costs $18 and that is 3 times as much as a blue hat costs. How much does a blue hat cost? Measurement example. A rubber band is stretched to be 18 cm long and that is 3 times as long as it was at first. How long was the rubber band at first? A red hat costs $18 and a blue hat costs $6. How many times as much does the red hat cost as the blue hat? Measurement example. A rubber band was 6 cm long at first. Now it is stretched to be 18 cm long. How many times as long is the rubber band now as it was at first? General a × b = ? a × ? = p, and p ÷ a = ? ? × b = p, and p ÷ b = ? Multiplicative compare problems appear first in Grade 4 (green), with whole number values and with the “times as much” language from the table. In Grade 5, unit fractions language such as “one third as much” may be used. Multiplying and unit language change the subject of the comparing sentence (“A red hat costs n times as much as the blue hat” results in the same comparison as “A blue hat is 1/n times as much as the red hat” but has a different subject.)