1.3 Operations

Quick Notes & Formulae

Essential concepts for solving operations problems.

Integer Operations
Addition: Same signs add, different signs subtract. (−a)+(−b)=−(a+b). Multiplication: (−)×(−)=(+), (−)×(+)=(−)
Decimal Arithmetic
Always line up decimal points for addition/subtraction. For multiplication, count total decimal places. For division, make divisor a whole number first.
Fraction Operations
Addition/Subtraction: Find common denominator first. Multiplication: Multiply numerators and denominators. Division: Multiply by the reciprocal.
Mixed Numbers
Convert to improper fractions before operating: abc=ac+bc. Convert back after calculation if needed.
Order of Operations
BODMAS: Brackets → Orders (powers/roots) → Division/Multiplication (left to right) → Addition/Subtraction (left to right)
Reciprocals
The reciprocal of ab is ba. Dividing by a fraction equals multiplying by its reciprocal: ab÷cd=ab×dc

Past Paper Style Questions

Question 1: Integer Operations (All Four Rules)

(a) Calculate: −12+25 [1]
(b) Calculate: −18−(−9) [1]
(c) Calculate: −7×8 [1]
(d) Calculate: −96÷12 [1]
(e) Explain, using a number line or otherwise, why subtracting a negative number is equivalent to adding a positive number. [2]

Question 2: Integers in Context (Temperature)

+5°C-5°CThe temperature at 6 am was −7∘C.
(a) By 10 am, the temperature had risen by 12∘C. Find the temperature at 10 am. [1]
(b) By 2 pm, the temperature had risen by a further 8∘C from the 10 am reading. Find the temperature at 2 pm. [1]
(c) By 10 pm, the temperature had fallen to −3∘C. Calculate the total change in temperature from 2 pm to 10 pm. [2]
(d) Calculate the mean temperature for the day using the four readings. [2]
(e) State whether the final temperature is above or below freezing point (0∘C). [1]

Question 3: Decimals - Addition and Subtraction

10.53TensUnits tenthshundredths
(a) Calculate: 8.35+4.7 [1]
(b) Calculate: 15−6.84 [1]
(c) Calculate: 3.06+0.85+2.4 [2]
(d) A piece of wood is 4.35 m long. If 1.8 m is cut off, find the remaining length. [1]
(e) Explain why lining up decimal points is essential when adding or subtracting decimals. [1]

Question 4: Decimals - Multiplication and Division

(a) Calculate: 0.7×0.6 [1]
(b) Calculate: 2.4×1.5 [1]
(c) Calculate: 5.6÷0.8 [1]
(d) Calculate: 0.084÷0.04 [2]
(e) A rectangle has length 3.5 m and width 2.4 m. Calculate its area. [2]
(f) Explain the rule for placing the decimal point when multiplying two decimals. [1]

Question 5: Fractions - Addition and Subtraction

(a) Simplify: 35+14 [2]
(b) Simplify: 78−12 [2]
(c) Calculate: 213+134 [3]
(d) Find the difference between 56 and 14. Give your answer in simplest form. [2]
(e) Explain why a common denominator is needed when adding or subtracting fractions. [1]

Question 6: Fractions - Multiplication and Division

(a) Calculate: 37×25 [1]
(b) Calculate: 49÷23 [2]
(c) Calculate: 112×49 [2]
(d) Calculate: 225÷113 [3]
(e) A recipe requires 34 cup of flour. How much flour is needed for 212 batches? [2]
(f) Explain why dividing by a fraction is the same as multiplying by its reciprocal. [1]

Question 7: Mixed Operations with Fractions

(a) Simplify: 12+23×34 [2]
(b) Simplify: (56−13)÷12 [3]
(c) Simplify: 34×25+12×35 [3]
(d) State which operation you performed first in part (a) and explain why. [1]
(e) A tank is 23 full of water. After using 14 of the water, what fraction remains? [3]

Question 8: Order of Operations - Integers and Decimals

BODMAS / PEMDASB - BracketsO - Orders (powers)DM - Divide/MultiplyAS - Add/Subtract
(a) Calculate: 8+6×4 [1]
(b) Calculate: (8+6)×4 [1]
(c) Calculate: 20−32×2 [2]
(d) Calculate: (1.5+2.5)×3−4.8÷1.2 [3]
(e) Insert brackets to make this statement true: 5+3×4−2=18 [1]
(f) Explain how brackets affect the value of an expression. [1]

Question 9: Order of Operations - Fractions

(a) Calculate: 13+25×56 [2]
(b) Calculate: (13+25)×56 [3]
(c) Calculate: 78−14÷12 [2]
(d) Calculate: 34×(23+16)−14 [3]
(e) State the order of operations used in part (c). [1]

Question 10: Mixed Exam-Style Problem

A school is organizing a trip. Each student needs to pay for transport, food, and an entrance fee.
Transport: $12.50|Food: $8.75|Entrance: $6.25
(a) Calculate the total cost for one student. [1]
(b) A group discount of 15 off the total is applied for groups of 10 or more. Calculate the discounted price per student. [3]
(c) There are 24 students in the group. Calculate the total amount collected. [2]
(d) The transport company charges a flat fee of $250 for the bus regardless of passenger numbers. Calculate how much money the school has left after paying for transport. [3]
(e) Identify where addition, subtraction, multiplication, and division are each used in this problem. [4]

Question 11: Integers and BIDMAS

(a) Calculate: −3+5×4 [1]
(b) Calculate: (−3+5)×4 [1]
(c) Calculate: 18÷(−3)−7 [1]
(d) Calculate: 23−4×(−2) [2]
(e) State one reason why the answers to (a) and (b) are different. [1]

Question 12: Integers in Context

A bank account has a balance of ₹450 in debt (−450).
A deposit of ₹800 is made, then a withdrawal of ₹675 is made.
(a) Find the balance after the deposit. [1]
(b) Find the balance after the withdrawal. [1]
(c) By how much did the balance change from the start to the end? [2]
(d) Is the final balance positive or negative? [1]

Question 13: Decimals - Exact and Estimate

(a) Calculate: 12.08+4.9−3.75 [2]
(b) Round each number in part (a) to 1 decimal place and estimate the result. [2]
(c) Compare your exact answer to your estimate. Is it reasonable? [1]
(d) State the exact answer correct to 2 decimal places. [1]

Question 14: Decimals - Multiplication and Division

(a) Calculate: 0.35×0.6 [1]
(b) Calculate: 7.2÷0.08 [1]
(c) Calculate: 3.75×1.2 [1]
(d) A number is multiplied by 0.6 and gives 9. Find the original number. [2]

Question 15: Fractions - Add, Subtract, Simplify

(a) Simplify: 712+518 [2]
(b) Simplify: 1115−25 [1]
(c) Write 138 as an improper fraction. [1]
(d) Hence find: 138+516 in simplest form. [2]

Question 16: Fractions - Multiply and Divide

(a) Calculate: 910×512 [1]
(b) Calculate: 79÷1427 [2]
(c) Write 214 as an improper fraction. [1]
(d) Hence calculate: 214÷38. [2]

Question 17: Mixed Fraction Operations and BIDMAS

(a) Calculate: 34+23×910 [3]
(b) Calculate: (56−14)×127 [3]
(c) Calculate: 78÷(12+14) [3]
(d) State which operation you do first in part (c) and why. [1]

Question 18: Decimals and Fraction Conversion

(a) Write 0.375 as a fraction in simplest form. [1]
(b) Calculate: 0.375+23 and give your answer as a fraction. [2]
(c) Convert your answer in part (b) to a decimal (3 d.p.). [1]
(d) State whether the decimal in part (c) is terminating or recurring. Give a reason. [2]

Question 19: Order of Operations with Decimals and Fractions

(a) Calculate: 6.4−1.2×3 [1]
(b) Calculate: (6.4−1.2)×3 [1]
(c) Calculate: 56+2×38 [2]
(d) Calculate: (56+2)×38 [2]
(e) Explain why (c) and (d) give different answers. [1]

Question 20: Exam-Style Multi-Step Problem

A recipe uses 34 of a cup of sugar per cake.
(a) How much sugar is needed for 6 cakes? Give your answer as a mixed number. [2]
(b) Sugar is sold in 2-cup bags. How many bags are needed for 6 cakes? [1]
(c) Each bag costs ₹58.50. Find the total cost for the bags needed. [1]
(d) A discount of ₹15 is applied. Find the final cost. [1]
(e) The final cost is shared equally between 3 people. How much does each person pay (₹, 2 d.p.)? [2]