Take away the tens and the ones, row by row. Each row works on its own.
Put the first number on the frame. Take away by sliding beads back, the tens row and the ones row each on its own.
Start with the tens: the tens row is the big place. Read the rows that are still across.
The ones row never touches the tens row, because each row works alone.
When nothing needs to be borrowed, tens first or ones first gives the same answer.
These are some of the questions on the sets. The printable sheets have more, with the bead frame drawn for each, and an answer key.
43. 7 tens take away 3 tens is 4 tens. 8 ones take away 5 ones is 3 ones.
44. 9 tens take away 5 tens is 4 tens. 6 ones take away 2 ones is 4 ones.
55. Only the tens row moves: 8 tens take away 3 tens is 5 tens. The 5 ones stay.
yes. The ones row has 2 beads and 8 must go, so you must borrow.
Ask a grown-up to pick a two-digit number and a smaller one, like seventy-eight and thirty-five, with every digit of the second no bigger than the digit above it. Take away the tens, then the ones, and check on paper or with a calculator.
Pick two numbers like 78 and 35, where each digit of the second is no bigger than the digit above it, and check the answer with a calculator.
