Grade Level: First

Content Area: Math

Standard: 

MA19.1.14 – Given a two-digit number, mentally find 10 more or 10 less than the number without having to count, and explain the reasoning used.

In this activity, students will find 10 more and 10 less than a number without counting. 

Objective: Students will build a paper plate number spinner to model tens and ones. Students will use the spinner to mentally find 10 more and 10 less and explain how the tens digit changes.

Directions: For this activity, students begin by writing ten two-digit numbers evenly spaced around the outer rim of a paper plate. Next, they cut out a paper arrow and attach it to the center of the plate with a brass fastener, creating a spinner. Students then spin the arrow to select a two-digit number and say the number out loud. To find 10 more, students mentally add one group of ten and explain that only the tens digit changes. To find 10 less, students mentally subtract one group of ten and explain that the tens digit decreases by one. 

Guidelines: During this STEM math activity, students create a paper plate spinner to practice mentally finding 10 more and 10 less of two-digit numbers. This hands-on STEM activity helps build strong number sense while keeping learning fun and engaging.