Measure word problems with fractions and decimals
Solve word problems involving distances, time intervals, liquid volumes, masses, and money using the four operations with fractions or decimals; represent with diagrams including number lines
What a learner can do afterwards
- A 2.5 kg bag of flour is split equally into 4 portions. What does each weigh?
- A journey takes 1 hr 45 min; what time do you arrive if you leave at 09:20?
- Three ribbons of 0.75 m, 1.2 m, and 0.95 m. What is the total length?
1 · Read
You already know how to compare money and use decimals for tenths and hundredths. Now you'll use those skills on real problems: measuring a journey, timing a trip, weighing ingredients, and adding up lengths. Ask what the story does first. Joining lengths means add. Sharing a total equally means divide. Finding what is left means subtract.
Add the three ribbon lengths by lining up the decimal points, so tenths sit under tenths and hundredths under hundredths. Write 1.2 as 1.20 to keep the columns full. Then 0.75 + 1.20 + 0.95 = 2.90, so the ribbons measure 2.9 m altogether. The same lining up works when you take one length away from another.
A 2.5 kg bag of flour is split equally into 4 portions. Since it's shared equally, divide: 2.5 ÷ 4 = 0.625 kg. Each portion weighs 0.625 kg.
A journey takes 1 hour 45 minutes and starts at 09:20. Add the whole hour first, so 09:20 becomes 10:20. Then add the 45 minutes: 20 + 45 = 65 minutes, which is more than 60, so carry an hour and keep the 5. You arrive at 11:05.
Draw the parts before you calculate. A quick bar, or a jump along a number line, shows whether your answer should be bigger or smaller than what you started with.
Word problems with fractions and decimals still use add, subtract, multiply, or divide. Line up the decimals, or the hours and minutes, before you work it out.
More to read
Multi-step measurement problems
Some problems need several steps before the answer shows. Read the whole story first and list what you know. A bag weighing 2.5 kg split into 4 equal parts means one division: 2.5 divided by 4. Check each step as you go. After dividing, multiply back to see 0.625 x 4 return to 2.5. Multi-step problems reward tidy working more than speed.
Metric units of volume review (L and mL)
Lengths with decimals add like money. Line up the decimal points, then add each column. 0.75 m + 1.2 m + 0.95 m gives 2.90 m, which we write as 2.9 m. Word problems hide additions in stories about ribbons, races, and recipes. Pull out the numbers with their units first. Then the arithmetic is just decimal adding.
Meters and centimeters
Time problems use hours and minutes instead of decimals. From 09:20, add 1 hour to reach 10:20, then 45 minutes to reach 11:05. Hop in two jumps and the arrival time is safe. Durations turn into minutes with one multiply. 2 minutes 30 seconds is 2 x 60 + 30 = 150 seconds. Change everything to the same unit before you add or subtract.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
Optional connections
This opens up
Where this leads
18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.