Encourage a strong home-to-school connection with curriculum-based Colorful Cut-Outs. Math Challenge: Number Sense-Primary Curriculum Cut-Outs helps students encourage essential math skills. This set includes 35 challenge cards and one answer key. Build the skills for success with fun, hands-on manipulatives. Our curriculum-based Colorful Cut-Outs are the perfect learning resource for the classroom and for the home. These convenient cut-outs can be used for independent practice, small-group instruction, and whole-class instruction. They are also a great addition to classroom learning centers!