Shift both numbers

Shift both numbers FAQs

Answers about Shift both numbers, including when to use the shortcut and what to practice next.

What is the Shift both numbers mental math strategy?

Shift both numbers is a subtraction shortcut for grades 3–4. Slide both numbers the same way. The gap doesn’t change — the math gets easier. Move both numbers by the same amount to make a friendly ten.

When should kids use Shift both numbers?

Use Shift both numbers when shifting both numbers makes a friendlier subtraction. The lesson on this page walks through that trigger with interactive examples.

How do you solve problems with Shift both numbers?

1. Add the same amount to both numbers. 2. Stop when the smaller number is a friendly ten. 3. Subtract. The difference stays the same. A worked pattern is 43 − 18 → 45 − 20 = 25.

What grades learn Shift both numbers?

Shift both numbers is taught for Grades 3–4. Younger or older learners can still use the same lesson if the numbers feel right.

How do I practice Shift both numbers after the lesson?

Open Shift both numbers flashcards at https://www.besparq.com/learn/mental-math/shift-both-numbers/flashcards for 20 cards with hints, then race the Shift both numbers speed sheet at https://www.besparq.com/learn/mental-math/shift-both-numbers/sheet — 50 problems in 5 minutes.

How is Shift both numbers different from Count up to find the difference?

Shift both numbers is for this trigger: Shifting both numbers makes a friendlier subtraction. Count up to find the difference is a different shortcut (Add up from the smaller number to the bigger one.). Compare them on https://www.besparq.com/learn/mental-math/count-up-difference/learn.