Number bonds
Recall number bonds (addition and related subtraction facts) within 20
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Teaching Table · Reviewed guide
Set out your lesson
“A number bond is a pair that makes a total. If 8+5=13, then 13-5=8. We use the addition fact to unlock the related subtraction fact.”
Bring to the table
- 20 counters or blocks
- Paper and marker
Full guide and materials
- 20 counters or blocks
- Paper and marker
- Step 1. Choose total 13. Build 8 and 5 with counters and say 8+5=13.
- Step 2. Hide the 5 and ask, “13 take away 5 leaves how many?” Aim for 8 from the bond.
- Step 3. Repeat with 10+2=12 and 12-2, then one total chosen by your child within 20.
- Step 4. Write one pair of related facts, such as 8+5=13 and 13-5=8.
- Quick check. Success means your child states at least one addition bond within 20 and the related subtraction fact without rebuilding from scratch every time.
Worked example. Bond 12 can be 10+2. Related subtraction: 12-2=10. Bond 15 can be 8+7, so 15-7=8.
Optional challenge. For 18, list two different bonds and one related subtraction for each.
What to notice. Save a parent note with one addition bond and its related subtraction fact.
Compare teaching approaches
Teaching approaches
Gakuva’s recommended starting approach is selected. You can still compare every option.
1 approach
A number bond is a pair that makes a total. If 8+5=13, then 13-5=8. We use the addition fact to unlock the related subtraction fact.
Spend about 10–15 minutes building bonds and flipping them into subtraction.
Family records and proof options
Keep a record of your learning
Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.
Learning resources
Reviewed external links that reinforce this concept. They do not replace Gakuva’s teaching approach.
Topmarks · Practice link — not the full lesson
Hit the Button · Number Bonds
Timed recall of addition and related subtraction partners. Choose Number Bonds and set the total within 20 for this concept.
Free · no login · ads · timed play
Review and open practice
Save a screenshot showing Number Bonds within 20 and a parent note listing two addition facts and their related subtraction facts the learner recalled.
Opening this link does not save learning or assess mastery.
Open practice (new tab)Source, access and review notes
Timed recall of addition and related subtraction partners. Choose Number Bonds and set the total within 20 for this concept.
Save a screenshot showing Number Bonds within 20 and a parent note listing two addition facts and their related subtraction facts the learner recalled.
Free · no login · ads · timed play
Unknown — link only
Visnos · Practice link — not the full lesson
Addition & Subtraction Facts
Animated number-line model for addition and subtraction facts through 20. Move penguins to see how parts recombine while the equation updates.
Free · no login · no ads observed
Review and open practice
Save a screenshot of a fact within 20 plus a parent note that the learner read the equation and stated the related subtraction fact.
Opening this link does not save learning or assess mastery.
Open practice (new tab)Source, access and review notes
Animated number-line model for addition and subtraction facts through 20. Move penguins to see how parts recombine while the equation updates.
Save a screenshot of a fact within 20 plus a parent note that the learner read the equation and stated the related subtraction fact.
Free · no login · no ads observed
Unknown — link only
Check understanding
- Quickly recall that 8 + 5 = 13
- Given 13 – 5, respond 8 using knowledge of related addition fact
- Know all pairs of single-digit numbers that sum to numbers up to 20
“Can your child quickly recall facts like '8 + 7 = 15' and immediately know that '15 − 7 = 8' — without having to work out the subtraction from scratch?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Addition & Subtraction
- Age range
- Ages 5–6
Standards