Ten in a full row trade for one bead on the next row up.
A row holds only ten beads. When a ones row fills up, ten ones trade for one bead on the tens row.
Slide the ten ones back and slide one bead up on the tens row. That ten that moves up is called a carry.
A full tens row trades too: ten tens trade for one hundred, so a carry can hop twice.
Add the ones first, trade when a row is full, then count the carried ten with the tens.
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.
44. 9 + 5 = 14: carry a ten and keep 4 ones. 2 + 1 + 1 = 4 tens.
83. 7 + 6 = 13: carry a ten and keep 3 ones. 5 + 2 + 1 = 8 tens.
105. 6 + 9 = 15: carry a ten and keep 5 ones. 7 + 2 + 1 = 10 tens, which trade for one hundred.
102. 5 + 7 = 12: carry a ten and keep 2 ones. 6 + 3 + 1 = 10 tens, which trade for one hundred.
Ask a grown-up for a pile of buttons or coins and a jar. Count out ten and swap them for one big button or one coin. Do it again until the pile is gone, and say how many swaps you made and how many were left over.
At home, trade ten small things (buttons, coins) for one big thing, so your child feels what a carry is.
