Maths addition stage 6

1. Problems like 73 – 19 = …..
I am learning to solve division problems like 73 - 19 = … by
first subtracting a tidy number and then adding on a small
number to get the answer.
Numbers like
10, 20, 30, 40
etc.

2. SAMPLE PROBLEM
A logging company has a field with 84 trees in it. They have
cut down 28 trees. How many trees have they left standing?
84 - 28 = …..
Number of
trees there
were.
Number of trees
that have been
cut down.
Number of trees that
are left.

3. SAMPLE PROBLEM
Step 1: Draw a number line and write in the total
amount of trees on the right hand side of the
number line.
84 - 28 = …..
Hint: Remember number lines always run from
smallest to largest.
84

4. SAMPLE PROBLEM
Step 2: Choose a tidy number which is
close to 28 and subtract this.
20 is a tidy number but it’s not
the closest tidy number to 28.
30 is a tidy number. This is
the best choice.
84 - 28 = …..
8454
Hint: When you subtract by a tidy number the
ones digit doesn’t change.
-20
-30

5. SAMPLE PROBLEM
Step 3: We took away 30 but we only needed to
take away 28. To fix this we must now jump back
up 2.
84 - 28 = …..
8454
-30
+2
56
Hint: You move down the number line (to the left) when subtracting
because the numbers are getting smaller and to the right when
adding because the numbers are getting bigger.
That means 84 – 28 = 56

6. Now let’s try one together
Andrew is carrying a tray with 63 eggs in it. He drops it and
27 break. How many eggs are not broken?
63 - ? = 27

7. Now let’s try one together
Step 1: Draw a number line with your starting
point. Do this now on a piece of paper.
63 - ? = 27

8. Now let’s try one together
Step 2: Choose a tidy number to jump back.
Remember this needs to be a tidy number which
is very close to 27. Do this now.
63 - ? = 27

9. Now let’s try one together
Step 3: Because we jumped back 30 we jumped a bit too far.
Work out how much we need to jump back up the number
line to fix this.
Add this to your drawing now.
63 - ? = 27

10. Now let’s try one together
Answer: What is the answer to our sample
question? Write this in now.
63 - ? = 27

11. Now try these questions on your own.
1) 76 – 19 = …..
2) 83 – 58 = ….
3) 67 – 38 = ….
4) 85 – 47 = ….
5) 58 – 29 = ….
6) 72 – 47 = ….
7) 93 – 39 = ….
8) 34 – 18 = ….
9) 64 – 28 = …
10) 75 – 37 = …

12. Only click again if you have completed all the questions
on the previous slide and you are ready to see the
answers.
1) 57
2) 25
3) 29
4) 38
5) 29
6) 25
7) 54
8) 16
9) 39
10) 38
Need some more practise? Try Pg51 of Teacher Tools Addition and
Subtraction Book Numeracy resources