The document states that a new armchair costs £781, and Christine has saved £308. To determine how much more Christine needs to save to buy the armchair, the document uses a number line to count up from £308 to £781, determining that the difference is £473.

1. A new armchair costs £781.
Christine has saved £308. How
much more does she need to save
to buy the armchair?

2. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
This is a subtraction sum!
£225 - £87 =

3. _______________________
• A new armchair costs £781. Christine has saved
£308. How much more does she need to save to
buy the armchair?
Firstly, put the numbers you are going
to use on the number line.
£781£308

4. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
Then, count on to the nearest ‘easy’
number
£781£308 £310
+2

5. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
…..and again
£781£308 £310
+2 +90
£400

6. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
…..keep going…..
£781£308 £310
+2 +90
£400
+300
£700

7. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
…..you’re not finished yet!…..
£781£308 £310
+2 +90
£400
+300
£700
+80
£780

8. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
…..one more step…..!
£781£308 £310
+2 +90
£400
+300
£700
+80
£780
+1

9. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
…..Excellent !
….but are we finished yet?
£781£308 £310
+2 +90
£400
+300
£700
+80
£780
+1

10. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
2+90+300+80+1 =
(Let’s make it easier though shall we?)
£781£308 £310
+2 +90
£400
+300
£700
+80
£780
+1

11. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
300+90+80+2+1=
(Let’s make it easier though shall we?)
£781£308 £310
+2 +90
£400
+300
£700
+80
£780
+1

12. _______________________
• A new armchair costs £781. Christine has saved £308.
How much more does she need to save to buy the
armchair?
300+90+80+2+1= 473
(Let’s make it easier though shall we?)
£781£308 £310
+2 +90
£400
+300
£700
+80
£780
+1