Solve a system of equations using substitution word problems

Learning Objectives Identify two unknown quantities in a consumer math word problem. Use given total information to make an educated guess for one unknown. Calculate the second unknown quantity based on their first guess and the total number of items. Substitute the calculated quantities into a total value equation to check their solution. Adjust their initial guess if the total value does not match the problem's given total. Clearly state the solution for both unknown quantities. Apply the substitution strategy to solve simple consumer math problems involving two different items with different costs. Have you ever wondered how stores keep track of how many different items they sell when they only know the total number of items and the total money earned? 💰 Let'...

TermDefinitionExample Unknown QuantityA value or number that you need to find in a problem. In our problems, there will be two unknown quantities.In the problem 'How many apples and how many bananas did I buy?', the number of apples and the number of bananas are the unknown quantities. Total NumberThe sum of all items or quantities mentioned in the problem.If you bought 3 apples and 5 bananas, the total number of fruits is 8. Total Value/CostThe total amount of money spent or earned for all items.If an apple costs $1 and a banana costs $0.50, and you bought 3 apples and 5 bananas, the total cost is $1(3) + $0.50(5) = $3 + $2.50 = $5.50. SubstitutionA strategy where you use information you already have (or a smart guess) to figure out another piece of information. You 'subst...

Identify the Unknowns and Totals Read the problem carefully to find the two items you need to count and the two total numbers given (total items and total value). Before you start solving, know what you're looking for and what information you have. This helps organize your thoughts. The 'Guess and Check' Substitution Strategy 1. Make a smart guess for the number of one item. 2. Use the total number of items to find the number of the second item. 3. Use the costs of each item to calculate the total value. 4. Compare your calculated total value to the problem's given total value. If they don't match, adjust your first guess and repeat! This is how we 'substitute' at Grade 5. We use our guess for one item to figure out the other, then check if...