Stage 8 of 20
Bridging Through Tens
Cross a ten boundary smoothly by landing on the ten, then adding or subtracting the remainder. Bridging keeps two-digit work tidy.
Land on the ten, then continue
For 28 + 7: 28 needs 2 to reach 30, so use 2 from the 7, then add the leftover 5 → 35. The same idea works for subtraction across tens.
Why this mental math skill matters
Bridging keeps addition and subtraction tidy when a calculation crosses a ten boundary. It prevents “lost place” errors in mental work.
Worked examples
Study each example slowly. Say the steps aloud — verbal rehearsal strengthens mental arithmetic memory.
28 + 7
- 28 + 2 = 30.
- Leftover from 7 is 5.
- 30 + 5 = 35.
Answer: 35
45 + 8
- 45 + 5 = 50.
- Leftover 3.
- 53.
Answer: 53
32 − 5
- 32 − 2 = 30.
- Still need to subtract 3.
- 27.
Answer: 27
Tips for success
- Ask: how many to the next ten?
- Use only what you need from the second number.
- Finish with the leftover on the far side of the ten.
Common mistakes to avoid
- Adding the full second number after already bridging.
- Bridging when a simpler make-ten path exists and getting tangled.
How to practice this stage
Pick problems that clearly cross a ten (like 28 + 7). Force the two-jump method until it feels automatic.
Interactive practice
Stage 8 Drill
Cross the ten boundary in two clean jumps.
Solve
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FAQ: Bridging Through Tens
What is bridging through ten?
It means landing on a ten first, then completing the remaining add or subtract with the leftover amount.
Does bridging help with subtraction?
Yes — for example, 32 − 5 can go 32 − 2 = 30, then 30 − 3 = 27.