Before you print
Big friends: what happens when a rod runs out of room
The Level 2 practice sheet: additions that carry past ten and therefore need the ten complements, known in most classrooms as the big friends. This is where a child stops counting and starts using the formulas properly. Answers are printed at the foot of the page.
The skill this sheet trains
A single rod holds nine and no more. Ask it for 9 plus 3 and it has nowhere to put the 3. The resolution is to look at what 9 is short of ten, which is 1, subtract that 1 from the units rod, and add one bead on the tens rod to the left. The pairs to know are 1 and 9, 2 and 8, 3 and 7, 4 and 6, and 5 with itself. Carrying is no longer a rule a child has been told to obey; it is something they can watch happen, one rod handing its overflow to the next. That visible mechanism is the reason abacus-trained children tend to be untroubled by place value later, and it is the whole content of this sheet.
Using the sheet
All twenty four problems cross ten, none of them by accident, so there is no easy item to warm up on. Expect twenty to twenty five minutes, and expect a first pass with several errors, which is normal and not a warning sign. Finished means the child can name the complement before they move, not after. A useful check part way through: cover the sheet and ask what 7 is short of ten. If the answer is instant, the formula has landed; if it needs counting, the sheet is doing arithmetic that the child is not yet ready to automate.
What to watch for
The classic Level 2 error is subtracting the complement and forgetting the carry, so 8 plus 5 comes back as 3 rather than 13. It is not carelessness. It means the two halves of the move are still two separate thoughts rather than one gesture, and the fix is slower repetitions of the same few pairs, not more problems. The opposite error, adding the carry but never removing the complement, is rarer and usually means the child has memorised the tens digit and is guessing the units.
Where it sits in the course
Level 2 is the second of the ten graded stages and the hinge of the early course. Children who are comfortable here move through Levels 3 and 4 noticeably faster, because multi-digit work is this same move repeated across rods. The graded syllabus sets out what level 2 covers.
What to print next
Multiplication starts to matter from here, and it rests on facts that need to be instant: Times Tables Sprint.
Abacus Level 2 Worksheets
Twenty four big friends problems that cross ten
Level 2 · Ages 6 to 10
Name: ______________________
Date: ______________________
- 1.9 + 3 = ______
- 2.8 + 5 = ______
- 3.7 + 6 = ______
- 4.6 + 7 = ______
- 5.9 + 8 = ______
- 6.8 + 9 = ______
- 7.7 + 8 = ______
- 8.6 + 6 = ______
- 9.9 + 9 = ______
- 10.8 + 8 = ______
- 11.7 + 7 = ______
- 12.6 + 5 = ______
- 13.9 + 2 = ______
- 14.8 + 4 = ______
- 15.7 + 4 = ______
- 16.6 + 9 = ______
- 17.9 + 5 = ______
- 18.4 + 8 = ______
- 19.3 + 9 = ______
- 20.2 + 9 = ______
- 21.8 + 6 = ______
- 22.4 + 9 = ______
- 23.6 + 8 = ______
- 24.7 + 9 = ______
Answers: 1) 12 · 2) 13 · 3) 13 · 4) 13 · 5) 17 · 6) 17 · 7) 15 · 8) 12 · 9) 18 · 10) 16 · 11) 14 · 12) 11 · 13) 11 · 14) 12 · 15) 11 · 16) 15 · 17) 14 · 18) 12 · 19) 12 · 20) 11 · 21) 14 · 22) 13 · 23) 14 · 24) 16