Breaking a Ten Apart

Not enough ones? Open a ten.

10 problems · about 13 minutes · 2.NBT.B.5, 2.NBT.B.9

NameDate

Figures — use these to answer the problems

There are not enough ones. Break a ten open first.

Start with

Taken away

What is left

Tens

Ones

62 − 27 = 35

Start with62

Take away27

Figure 1

Break a ten here too. The number at the top never moves.

Tens

Ones

How many62

Figure 2

From earlier lessons. Loosen up before the new work.

3 problems

From “Subtracting Tens and Ones”
95 − 32 = ?
Answer
2
From “Explaining Why It Works”
Someone says the bundled ten is "a one". Are they right?
- No. It is one ten.
- Yes. It is a one.
From “Adding Past 100”
58 + 67 = ?
Answer

Straightforward practice. Get the method working first.

3 problems

6 tens and 12 ones is which number?
Answer
5
When do you need to break a ten open?
- When there are not enough ones.
- Every time you subtract.
3 tens and 14 ones is which number?
Answer

The same ideas with more to keep track of.

1 problem

Mixed problems. Work out what kind of question it is before you start.

3 problems

8
Does breaking a ten change the amount?
- No. It is only rearranged.
- Yes. It gets smaller.
Another Way to Show It
4 tens and 13 ones is which number?
Answer
Opening One Up
85 has a ten broken open. How many ones are there now?
Answer