Multiply a 2-digit number by a 2-digit number: word problems

Learning Objectives Identify multiplication keywords and phrases in word problems. Translate word problems into numerical multiplication expressions involving two 2-digit numbers. Apply the standard algorithm to accurately multiply two 2-digit numbers. Solve multi-step word problems that include 2-digit by 2-digit multiplication. Estimate products to check the reasonableness of their answers to word problems. State the final answer to a word problem with appropriate units and context. Ever wonder how many cookies you'd need for a big party if each guest eats a certain amount? 🍪 Let's find out how to solve these kinds of puzzles! In this lesson, you'll learn how to tackle word problems that require multiplying two 2-digit numbers. We'll explore strategie...

TermDefinitionExample ProductThe result obtained when two or more numbers are multiplied together.In the equation 15 x 20 = 300, the number 300 is the product. FactorA number that is multiplied by another number to get a product.In the equation 15 x 20 = 300, the numbers 15 and 20 are factors. KeywordsSpecific words or phrases in a word problem that often indicate which mathematical operation to use.Words like 'each', 'per', 'every', 'times', 'total in all' often suggest multiplication. EstimationFinding an approximate value that is close to the exact answer, usually by rounding numbers.To estimate 23 x 48, you could round to 20 x 50 = 1000 to get a rough idea of the answer. Standard AlgorithmA step-by-step method for performing multiplica...

Standard Multiplication Algorithm (2-digit by 2-digit) $$(10a + b) \times (10c + d) = (10a + b) \times d + (10a + b) \times 10c$$ To multiply two 2-digit numbers, first multiply the top number by the ones digit of the bottom number. Then, multiply the top number by the tens digit of the bottom number (remembering to add a zero placeholder for the tens place). Finally, add the two partial products to get the total product. Interpreting Multiplication Word Problems Identify situations where a quantity is repeated a certain number of times or where you need to find a total amount from equal groups. Look for keywords such as 'each', 'per', 'every', 'times', 'total in all', or scenarios involving arrays, area, or multiple groups o...