64 take away 30 leaves 34: three tens and four ones.
The big ideaPicture the beads. Take tens first, then ones. A short ones row breaks a ten.
How it works
Picture the first number on the frame. Take the tens first, then the ones.
Tens come off the tens row, so only that row moves back.
If the ones row is short, break one ten into ten ones.
Check your answer on a real frame or on paper.
The plan for taking away in your head.52 − 7: a ten broke into ten ones, leaving forty-five.
Example 1: Taking tens: 64 − 30
Picture 64: six tens and four ones.
Thirty is three tens, so three beads slide back on the tens row.
Three tens and four ones are left.
64 − 30 = 34.
Example 2: Taking ones: 34 − 3
Picture 34.
Three ones slide back: four take away three leaves one.
34 − 3 = 31.
Example 3: Breaking a ten: 52 − 7
Picture 52: five tens and two ones.
Seven is more than two, so the ones row is short.
Take the two first. Five are still to take.
Break one ten into ten ones and take five of them.
Four tens and five ones are left: 52 − 7 = 45.
After the break: 45.
Example 4: Tens, then a break: 81 − 26
Take the two tens first: 81 − 20 = 61.
Now take six from the one one. The ones row is short.
Take the one, then break a ten and take five more.
81 − 26 = 55.
Example 5: No break: 86 − 32
Take the tens: 86 − 30 = 56.
Take the ones: six take away two is four, so nothing breaks.
86 − 32 = 54.
Words to know
take away
Slide beads back to leave fewer.
break a ten
Slide one tens bead back and it becomes ten ones.
short
A ones row with fewer beads than you need to take.
mental
Done in your head, with a picture of the frame.
Watch out
Tens come off the tens row, not the ones row.
Do not take the smaller ones digit from the bigger one. 62 − 8 = 54, not 66.
Take the tens first, then the ones.
Not every take-away breaks a ten. 86 − 32 does not.
Try it
What is 75 − 20?
Does 62 − 8 need a break?
What is 71 − 4?
What is 93 − 47?
Answers: 1. 55 · 2. Yes · 3. 67 · 4. 46
Try at homeAsk a grown-up to say a take-away to ninety-nine, like seventy-two take away twenty. Close your eyes and picture the frame. Say your answer, then check on a real frame or on paper. Swap turns!
For grown-upsSay a take-away to ninety-nine, like 72 − 20. Your child shuts their eyes, pictures the frame and says the answer, then checks on a real frame or on paper. Swap turns.
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