Twelve ones is a new ten

What this lesson shows

Fixes a mistake

56 + 6 makes 5 tens and 12 ones. That is 62, not 512.

The worked example

The lesson works this one step by step: 56 + 6 = □. Then your kid tries one like it on paper.

The steps

1. Add the ones
2. Trade 10 ones for a ten
3. One digit in each place

Helping at home

Each place holds one digit. When the ones make 10 or more, trade 10 of them for a ten, then write the tens and the ones left.

If your kid gets stuck

Each place holds one digit.

Standards

• Common Core 1.NBT.C.4
  Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.

More in this unit

• Adding ones to a two-digit number
• Get to the next ten
• Count back to the ten
• Open a ten
• The ten you opened is gone
• Take away tens