Chapter 1: Review

The chapter problem, solved

The stall spent

and took

so the profit was

The stall made a profit of £39.20. The cash box should hold the float plus the takings minus the spending:

Notice that the same answer comes from $50 + 39.20 = £89.20$: the cash box is the float plus the profit.

Mixed practice — choose the method first

For each question, say which method you will use before you calculate.

1. Write the value of the digit $4$ in $6\,048.2$.

2. Work out $(-7) + 2 - (-5)$.

3. Work out $48 \times 25$.

4. Work out $3 + 6 \times (10 - 4)$.

5. Round $2\,847$ to 2 significant figures.

6. Work out $7.2 - 9.5$.

7. Estimate $29 \times 41$.

8. Work out $0.6 \times 1000$.

9. A shop buys 40 T-shirts at £4.50 each and sells them all at £7.00 each. Work out the profit.

10. A lift starts at floor $-2$, goes up 9 floors, then down 4 floors. Which floor is it on?

11. Round $0.396$ to (a) 2 decimal places, (b) 1 significant figure.

12. Write an expression for the total of $6$ items at $£1.85$ each plus $4$ items at $£0.65$ each, then evaluate it.

What you can now do

• read, compare and order numbers using place value;
• use the four operations with integers and decimals, and check with inverses;
• work with negative numbers and interpret them in context;
• evaluate an expression in the correct order;
• round and estimate, and use an estimate to check an exact answer.

Your relevance reflection

Return to the prompt from the chapter opener: where in your own week do you meet negative numbers, or need a quick estimate before deciding something? Write one more example now that you have finished the chapter. Has the chapter changed what you notice?