Place Value Problem-Solving
Solve number and practical problems involving place value with increasingly large positive numbers
What a learner can do afterwards
- Solve a problem requiring rounding, comparing, or ordering numbers beyond 1000
- Apply place-value knowledge in a practical context (e.g. population figures, distances)
- Explain the strategy used, referencing place-value understanding
1 · Read
Big numbers show up everywhere, from city populations to river lengths. When a problem asks you to compare, order, or round these numbers, place value is your tool. If one number has more digits than another, it is bigger. Look at which digit sits in which place. To round, look at the digit after the place you round to. Five or more rounds up. Four or less rounds down.
Two towns report their populations: Elmwood has 18,430 people, and Fairview has 18,340. Which is bigger? Compare place by place. Both have 1 ten-thousand and 8 thousands, so move to the next digit: Elmwood has 4 hundreds, Fairview has 3. Since 4 is more than 3, Elmwood is bigger, even though its other digits are smaller. To order three numbers, compare two, then compare the winner with the third.
When comparing or ordering numbers, start from the leftmost digit, the one with the highest place value. Only move to the next digit if the first ones match.
To solve place-value problems, compare digits starting from the highest place value, and round when a big number needs to be made easier to work with.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
17 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.