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Rounding money. 19/02/14. How and why do we round money?. We use money everyday and sometimes we need to make adding and subtracting prices easier for ourselves! Can you think of some examples in life when we need to round money to the nearest dollar?. A Real life example.
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Rounding money 19/02/14
How and why do we round money? • We use money everyday and sometimes we need to make adding and subtracting prices easier for ourselves! • Can you think of some examples in life when we need to round money to the nearest dollar?
A Real life example • Here is a shopping list from the supermarket. I want you to work out a rough estimate of how much money I spent. But to make it quicker for yourselves you will need to round the money to the nearest dollar… Milk $2.95 Cheese $4.75 Lettuce $3.30 Tomatoes $2.25 Chocolate $5.50 Ice-cream $6.90 Bread $4.45 Ham $3.35 Clinkers $2.95 Oranges $4.40
The strategy… • When we round money we need to think about the magic number 0.50 or we can think of it as 50 cents. We don’t need to worry about the dollars, just the cents. • There is a basic strategy to rounding money: If there are LESS than 50 cents or 0.50 in the amount then we round the amount DOWN to the nearest dollar and; • If there are MORE than or EQUAL to 50 cents or 0.50 in the amount then we round the amount UP to the nearest dollar. Let’s have a go together…
Rounding up • If a bag of lollies cost $2.60 then there are more than 50 cents or 0.50 in this amount so we would round up to the nearest dollar. So we would round it up to $3.00
Rounding up • If a can of sprite cost $3.50 , it would be equal to 50 cents or 0.50 in this amount so we would round it up to the nearest dollar to make it $4.00
Rounding down • If a new DVD cost $22.30 then it would be less than 50 cents or 0.50 in the amount so we would round down to the nearest dollar and make it $22.00.
Warm up your brains… • Let’s have a go at rounding these amounts to the nearest dollar. Think about the answer in your head and don’t call out! • $4.85 4. $22.50 • $9.30 5. $1.90 • 3. $ 14.20 6. $104.30
Back to my shopping list • Ok so now you are going to have a go at rounding up the prices on my shopping list and then give me a estimate of how much I spent. Remember this is not the exact amount I spent but a rough guide to quickly working out how much money I spent.
Off you go! Milk $2.95 Cheese $4.75 Lettuce $3.30 Tomatoes $2.25 Chocolate $5.50 Ice-cream $6.90 Bread $4.45 Ham $3.35 Clinkers $2.95 Oranges $4.40
Change please? • I had $50 to pay for all these groceries. How much change did I get?