Counting forwards and backwards (age 9+)
Count forwards and backwards in steps of powers of 10 (10, 100, 1000, 10,000, 100,000) for any given number up to 1,000,000
What a learner can do afterwards
- Count on in 10,000s from 462,000
- Count back in 100,000s from 800,000
- Identify the next three terms: 375,000; 475,000; 575,000; ...
1 · Read
Counting by 1s takes forever with big numbers. Instead, you can count in steps of 10, 100, 1,000, 10,000, or 100,000. Find the digit in that step's place, then add or subtract from it. The rest of the number usually stays the same.
Zara starts at 930,000 and counts back in 100,000s: 930,000, 830,000, 730,000, 630,000. Each jump only changes the hundred-thousands digit.
When a step pushes a digit past 9, the next digit up changes too. Counting on in 10,000s from 195,000 gives 205,000. Counting back in 10,000s from 205,000 gives 195,000. Check the next place when a digit passes 9.
Counting in big steps means jumping straight to the right digit, forward or backward, and watching for digits that roll into the next place.
Reading, media and flashcards imported from the hoofer-content corpus. ExtraItems x1-x9 authored original for this topic; x1-x9 rewritten in the topic author's own words.
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.