Solve the following problems, showing all your working out.

a) $31 + 78$
Round 31 to the nearest 10: 30
Round 78 to the nearest 10: 80

$$30 + 80 = \boxed{110}$$

b) $137 - 56$
Round 137 to the nearest 10: 140
Round 56 to the nearest 10: 60

$$140 - 60 = \boxed{80}$$

a) $589 - 213$
Round 589 to the nearest 100: 600
Round 213 to the nearest 100: 200

$$600 - 200 = \boxed{400}$$

b) $621 + 273$
Round 621 to the nearest 100: 600
Round 273 to the nearest 100: 300

$$600 + 300 = \boxed{900}$$

$$583 + 294 = 500 + \boxed{80} + 3 + 200 + 90 + \boxed{4}$$ $$= 500 + 200 + \boxed{80} + 90 + 3 + \boxed{4}$$ $$= 700 + \boxed{170} + \boxed{7}$$ $$= \boxed{877}$$

a) $189 - 47$
Calculation:

$$189 - 47 = \boxed{142}$$

Check (addition):

$$142 + 47 = 189$$

b) $632 + 179$
Calculation:

$$632 + 179 = \boxed{811}$$

Check (subtraction):

$$811 - 179 = 632$$

Total eggs initially:

$$103 \text{ (white)} + 58 \text{ (brown)} = 161 \text{ eggs}$$

Eggs given away:

$$161 \text{ (total)} - 49 \text{ (left)} = \boxed{112 \text{ eggs}}$$

a) Write the rule for this flow diagram in words.
The rule is: Multiply the input number by 5, then add 3 to the result.

b) Use the flow diagram to fill in the missing values in the table.

• For Input 1: $(1 \times 5) + 3 = 5 + 3 = 8$
• For Input 2: $(2 \times 5) + 3 = 10 + 3 = 13$
• For Input 3: $(3 \times 5) + 3 = 15 + 3 = 18$
• For Input 4: $(4 \times 5) + 3 = 20 + 3 = 23$
• For Input 5: $(5 \times 5) + 3 = 25 + 3 = 28$

Input number	1	2	3	4	5
Output number	8	13	18	23	28

The rule is: Add 2, then multiply by 3.

• For Input 1: $(1 + 2) \times 3 = 3 \times 3 = \boxed{9}$
• For Input 2: $(2 + 2) \times 3 = 4 \times 3 = \boxed{12}$
• For Input 3: $(3 + 2) \times 3 = 5 \times 3 = \boxed{15}$
• For Input 5: $(5 + 2) \times 3 = 7 \times 3 = \boxed{21}$
• For Input 10: $(10 + 2) \times 3 = 12 \times 3 = \boxed{36}$