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.
Circle every row that is too short in 534 - 278. the hundreds row / the tens row / the ones row
True or false? Borrowing twice is just two trades, one after the other.
Ben did 531 - 247 and got 316. What did he do? He took the smaller digit from the bigger one in every row / He borrowed too many times / He added
Nothing to lend in two rows. 800 - 365 = ___
Which sum needs no borrow? nine hundred thirty-four take away five hundred twenty-one / six hundred thirty-two take away four hundred fifteen / four hundred twenty-three take away one hundred eighty-seven
Words to know
borrow
Trade one bead down for ten on the row below.
too few
A row that has fewer beads than the number to take away.
hundreds row
The top row. Each bead is worth a hundred.
open
Slide a bead down to trade it for ten on the row below.
Watch out for
Look at each row before you start: which rows are too short?
Work from the ones up to the hundreds, row by row.
After a row lends a ten, it has one fewer bead. Count that before you take away from it.
Try it
What is 375 - 142?
233. No row is too short: 3 - 1 = 2 hundreds, 7 - 4 = 3 tens, 5 - 2 = 3 ones.
What is 462 - 138?
324. Open a ten: 12 - 8 = 4 ones. Then 5 - 3 = 2 tens, and 4 - 1 = 3 hundreds.
What is 541 - 267?
274. Open a ten: 11 - 7 = 4 ones. Open a hundred: 13 - 6 = 7 tens. Then 4 - 2 = 2 hundreds.
What is 602 - 345?
257. The tens row has nothing to lend, so open the hundred first, then a ten. 12 - 5 = 7, 9 - 4 = 5, 5 - 3 = 2.
For grown-ups
Ask a grown-up to help you sort a pile of cards or stickers into groups of one hundred, groups of ten, and singles. Give some to a friend. Which group did you have to open?
Sort a pile of cards or stickers into hundreds, tens and singles. Give some away and ask which group your child had to open.
