Decimal Operations Mission Lab
Complete real-world missions using decimal math. Estimate first, then calculate the exact answer and see how close you were.
Choose Your Mission
School Supply Shopping
You are shopping for school supplies. Add the prices to find the total cost.
Maria bought a notebook for $2.45 and a pen for $1.29. How much did she spend in total?
Answer in Base-Ten Blocks (3.74)
Controls
Navigate between missions and problems above. Use "Record to Table" to log each result after checking.
Data Table
(0 rows)| # | Problem | Estimate | Exact Answer | Error | Operation |
|---|
Guided Experiment: Decimal Operations Investigation
Before solving, estimate by rounding each number to the nearest whole number. How close do you think your estimate will be to the exact answer?
Write your hypothesis in the Lab Report panel, then click Next.
Complete the missions above, recording your results in the data table.
Pay attention to how close your estimates are to the exact decimal answers.
Reference Guide
Adding Decimals
Line up the decimal points, then add each column from right to left, just like adding whole numbers.
Example: 2.45 + 1.29 = 3.74
Subtracting Decimals
Line up the decimal points and subtract. You may need to borrow from the next place value, just like with whole numbers.
Example: 16.47 − 14.82 = 1.65
Multiplying Decimals
Multiply as if there are no decimal points, then count the total decimal places in both factors and place the decimal in the answer.
Example: 8.50 × 3 = 25.50
Dividing Decimals
When dividing a decimal by a whole number, perform the division normally and keep track of the decimal point in the quotient.
Example: 2.4 ÷ 3 = 0.80