TEACHER EDITION
Dividing by 10, 100, and 1,000
Math Book 5 · sheet 3
Warm-up — yesterday: Multiplying by 10, 100, and 1,000
Show 74 × 100.7,400
What we are learning
Dividing by ten moves every digit one place to the RIGHT — the same chart, the other direction.
How it is done — keep this beside you
These steps stay on your page while you work. If you get stuck, find the step you are on and read it again before you put your hand up.
1
4,200 in the chart.
| 4 | 2 | 0 | 0 |
2
Divide by ten: everything shifts one place right.
| 4 | 2 | 0 | 0 |
420
3
The zero on the end was holding a place that is no longer needed.
| 4 | 2 | 0 | 0 |
420
420
4
Divide by ten again.
| 4 | 2 | 0 | 0 |
420
420
42
5
So ÷ 100 is two shifts right.
| 4 | 2 | 0 | 0 |
420
420
42
4,200 ÷ 100 = 42
Practice
I DOteacher builds it, nothing erased
3,600 ÷ 100
- Two shifts right.
- 36
WE DO 1together, on whiteboards
85,000 ÷ 1,000
Three shifts. Boards up when every digit has landed.
- 85
WE DO 2together, on whiteboards
9,040 ÷ 10
There is a zero inside this number, not just on the end.
- 904
YOU DOindependent, from the book
Book 5A p.12 — the Do section, clipped onto the slide
Ask yourself: “Which direction, and how many places?”
Watch for
9,040 is chosen because 'cross off a zero' takes the wrong one. The shift is the method; deleting zeros is a trick that breaks here and the child can see it break.
9,040 is chosen because 'cross off a zero' takes the wrong one. The shift is the method; deleting zeros is a trick that breaks here and the child can see it break.