- 4% Off

Safe and Secure Checkout
(edit with the Customer Reassurance module)
(edit with the Customer Reassurance module)
* Delivery to Metro Manila addresses may take up to 3-5 working days. Provincial deliveries may take 7 working days or longer.
* Not Applicable for Pre-Order or Special Order Items
* Deliveries during sale promotions and holiday seasons may take longer than usual.
* National Book Store may postpone processing and deliveries in case of flood and other natural disasters to ensure the safety of its personnel.
Call us (632) 8-8888-627
Mon-Sun 8AM-8PM
Each topic has been designed to include essential concepts that are covered within
each topic. Within each topic, there are several worked examples followed by 2 parallel questions to ensure reinforcement and enable students to grasp these concepts on their own.
Questions are also scaffolded so that students are able to experience solving
problem sums of varying difficulty level from basic to challenging questions.
This series of books is curated to assist students in grasping the following concepts
by using model drawing:
• before and after concepts
• items repeated
• same beginning and end
• internal transfers
• working backwards
Data sheet