Find and make amounts within 20 p | Maths | Quizalize & Oak National Academy

Starter quiz

What is the total value of these coins? ______ p

'9' ✓
Which set of coins could you use to pay for the teddy?
What is the total value of this set of coins? ______ p

'8' ✓
Which coins show a total of 10 p?
Aisha wants to pay for a toy costing 9 p in the most efficient way. Which set of coins should she choose?
Alex has some coins which have a total value of 7 p. One of his coins is a 5 p coin. Which other coin does he need?

5 p coin

1 p coin

2 p coin ✓

Exit quiz

Which coins show the most efficient way to make 12 p?
Which coins show the most efficient way to make 12 p without using a 10 p coin?
Which totals can be made using these coins? (You only have one of each.)

11 p

12 p ✓

14 p

15 p ✓
Which item can Alex buy using only two coins?
True or false. The most efficient way to make 15 p is by using three 5 p coins.

True
False ✓
Which coins show a total value of 20 p?

Worksheet

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Lesson Details

Key learning points

A combination of different coins can be used to make the same total value.
It is more efficient to use fewer coins to pay for an item.
Using coins of a greater value where possible will result in fewer coins being used.
With prices between 10 p and 20 p, partitioning the price into '10 and a bit' allows more efficient working.

Common misconception

Children may start counting out using any coins available instead of thinking of the whole amount needed first and partitioning it into manageable parts where they can deploy known strategies.

Encourage children to partition teen numbers using a part-part-whole model and use what they know about making 10, and the numbers up to 10, to find combinations that use the fewest possible coins to total a given value.

Keywords

Total value - Where referring to money, value refers to how much something is worth. The total value can be found by adding the value of each coin in a set.
Efficiently - Not wasting time or effort. An efficient strategy is one we can carry out easily.