Add, subtract, multiply, and divide decimals: word problems

Learning Objectives Identify the correct operation (addition, subtraction, multiplication, or division) required to solve decimal word problems. Translate real-world scenarios involving decimals into mathematical expressions. Accurately add and subtract multi-digit decimals in problem-solving contexts. Perform precise multiplication and division of decimals, including by powers of ten, within word problems. Estimate answers to decimal word problems to check for reasonableness. Interpret the results of decimal calculations in the context of the original word problem. Ever wondered how stores calculate your change or how much fuel you need for a trip? ⛽️ Decimals are everywhere, and mastering them helps you navigate daily finances and measurements! In this lesson, we'll...

TermDefinitionExample DecimalA number that includes a whole number part and a fractional part, separated by a decimal point.3.14 (3 is the whole number, 14 is the fractional part) Word ProblemA mathematical problem presented in a narrative form, requiring interpretation to set up and solve.Sarah bought 2.5 pounds of apples at $1.20 per pound. How much did she spend? KeywordsSpecific words or phrases in a word problem that indicate which mathematical operation to use."total," "sum" (addition); "difference," "left" (subtraction); "each," "per" (multiplication/division); "share," "split" (division). EstimationApproximating a value or calculation to quickly check for reasonableness.To estimate 4.8 x 2.1, think 5 x...

Adding/Subtracting Decimals Align the decimal points vertically, then add or subtract as with whole numbers. Essential for ensuring that digits of the same place value are combined correctly. Multiplying Decimals Multiply the numbers as if they were whole numbers. Count the total number of decimal places in the factors, then place the decimal point in the product that many places from the right. This rule accounts for the fractional parts of the numbers being multiplied. Dividing Decimals If the divisor is a decimal, move its decimal point to the right until it is a whole number. Move the dividend's decimal point the same number of places to the right. Then divide as with whole numbers, placing the decimal point in the quotient directly above the new decimal point...